diff --git a/RvtVa3c/Command.cs b/RvtVa3c/Command.cs
index 3b2392d..675dce8 100644
--- a/RvtVa3c/Command.cs
+++ b/RvtVa3c/Command.cs
@@ -1,165 +1,393 @@
 #region Namespaces
 using System;
+using System.Windows.Interop;
 using System.Collections.Generic;
 using System.Diagnostics;
 using System.IO;
+using System.Drawing;
 using Autodesk.Revit.ApplicationServices;
 using Autodesk.Revit.Attributes;
 using Autodesk.Revit.DB;
 using Autodesk.Revit.UI;
 using Autodesk.Revit.UI.Selection;
+using System.Windows.Forms;
 using SaveFileDialog = System.Windows.Forms.SaveFileDialog;
 using DialogResult = System.Windows.Forms.DialogResult;
-#endregion // Namespaces
+using System.Linq;
+
+
+
+#endregion
 
 namespace RvtVa3c
 {
-  [Transaction( TransactionMode.Manual )]
-  public class Command : IExternalCommand
-  {
-    /// <summary>
-    /// Custom assembly resolver to find our support
-    /// DLL without being forced to place our entire 
-    /// application in a subfolder of the Revit.exe
-    /// directory.
-    /// </summary>
-    System.Reflection.Assembly
-      CurrentDomain_AssemblyResolve(
-        object sender,
-        ResolveEventArgs args )
+    [Transaction(TransactionMode.Manual)]
+    public class Command : IExternalCommand
     {
-      if( args.Name.Contains( "Newtonsoft" ) )
-      {
-        string filename = Path.GetDirectoryName(
-          System.Reflection.Assembly
-            .GetExecutingAssembly().Location );
+        /// <summary>
+        /// Custom assembly resolver to find our support
+        /// DLL without being forced to place our entire 
+        /// application in a subfolder of the Revit.exe
+        /// directory.
+        /// </summary>
+        System.Reflection.Assembly
+          CurrentDomain_AssemblyResolve(
+            object sender,
+            ResolveEventArgs args)
+        {
+            if (args.Name.Contains("Newtonsoft"))
+            {
+                string filename = Path.GetDirectoryName(
+                  System.Reflection.Assembly
+                    .GetExecutingAssembly().Location);
+
+                filename = Path.Combine(filename,
+                  "Newtonsoft.Json.dll");
 
-        filename = Path.Combine( filename,
-          "Newtonsoft.Json.dll" );
+                if (File.Exists(filename))
+                {
+                    return System.Reflection.Assembly
+                      .LoadFrom(filename);
+                }
+            }
+            return null;
+        }
 
-        if( File.Exists( filename ) )
+        /// <summary>
+        /// Export a given 3D view to JSON using
+        /// our custom exporter context.
+        /// </summary>
+        public void ExportView3D(View3D view3d, string filename)
         {
-          return System.Reflection.Assembly
-            .LoadFrom( filename );
+            AppDomain.CurrentDomain.AssemblyResolve
+              += CurrentDomain_AssemblyResolve;
+
+            Document doc = view3d.Document;
+
+            Va3cExportContext context
+              = new Va3cExportContext(doc, filename);
+
+            CustomExporter exporter = new CustomExporter(
+              doc, context);
+
+            // Note: Excluding faces just suppresses the 
+            // OnFaceBegin calls, not the actual processing 
+            // of face tessellation. Meshes of the faces 
+            // will still be received by the context.
+
+            exporter.IncludeFaces = false;
+
+            exporter.ShouldStopOnError = false;
+
+            exporter.Export(view3d);
         }
-      }
-      return null;
-    }
 
-    /// <summary>
-    /// Export a given 3D view to JSON using
-    /// our custom exporter context.
-    /// </summary>
-    public void ExportView3D( View3D view3d, string filename )
-    {
-      AppDomain.CurrentDomain.AssemblyResolve
-        += CurrentDomain_AssemblyResolve;
 
-      Document doc = view3d.Document;
+        public static ParameterFilter _filter;
+        public static bool _filterParameters = false;
+        public static TabControl _tabControl;
+        public static Dictionary<string, List<string>> _parameterDictionary;
+        public static Dictionary<string, List<string>> _toExportDictionary;
+        public static bool includeT = false;
 
-      Va3cExportContext context
-        = new Va3cExportContext( doc, filename );
+        /// <summary>
+        /// Function to filter the parameters of the objects in the scene
+        /// </summary>
+        /// <param name="doc">Revit Document</param>
+        /// <param name="includeType">Include Type Parameters in the filter dialog</param>
+        public void filterElementParameters(Document doc,bool includeType)
+        {
+            _parameterDictionary = new Dictionary<string, List<string>>();
+            _toExportDictionary = new Dictionary<string, List<string>>();
 
-      CustomExporter exporter = new CustomExporter(
-        doc, context );
+            FilteredElementCollector collector = new FilteredElementCollector(doc, doc.ActiveView.Id);
 
-      // Note: Excluding faces just suppresses the 
-      // OnFaceBegin calls, not the actual processing 
-      // of face tessellation. Meshes of the faces 
-      // will still be received by the context.
+            // create a dictionary with all the properties for each category
+            foreach (var fi in collector)
+            {
 
-      exporter.IncludeFaces = false;
+                string category = fi.Category.Name;
 
-      exporter.ShouldStopOnError = false;
+                if (category!= "Title Blocks" && category!="Generic Annotations" && category != "Detail Items" && category!= "Cameras")
+                {
+                    IList<Parameter> parameters = fi.GetOrderedParameters();
+                    List<string> parameterNames = new List<string>();
 
-      exporter.Export( view3d );
-    }
+                    foreach (Parameter p in parameters)
+                    {
+                        string pName = p.Definition.Name;
+                        string tempVal = "";
 
-    #region SelectFile
-    /// <summary>
-    /// Store the last user selected output folder
-    /// in the current editing session.
-    /// </summary>
-    static string _output_folder_path = null;
-
-    /// <summary>
-    /// Return true is user selects and confirms
-    /// output file name and folder.
-    /// </summary>
-    static bool SelectFile(
-      ref string folder_path,
-      ref string filename )
-    {
-      SaveFileDialog dlg = new SaveFileDialog();
+                        if (StorageType.String == p.StorageType)
+                        {
+                            tempVal = p.AsString();
+                        }
+                        else
+                        {
+                            tempVal = p.AsValueString();
+                        }
+                        if (!string.IsNullOrEmpty(tempVal))
+                        {
+                            if (_parameterDictionary.ContainsKey(category))
+                            {
+                                if (!_parameterDictionary[category].Contains(pName))
+                                {
+                                    _parameterDictionary[category].Add(pName);
+                                }
+                            }
+                            else
+                            {
+                                parameterNames.Add(pName);
+                            }
+                        }
+                    }
+                    if (parameterNames.Count > 0)
+                    {
+                        _parameterDictionary.Add(category, parameterNames);
+                    }
+                    if (includeType)
+                    {
+                        ElementId idType = fi.GetTypeId();
 
-      dlg.Title = "Select JSON Output File";
-      dlg.Filter = "JSON files|*.js";
+                        if (ElementId.InvalidElementId != idType)
+                        {
+                            Element typ = doc.GetElement(idType);
+                            parameters = typ.GetOrderedParameters();
+                            List<string> parameterTypes = new List<string>();
+                            foreach (Parameter p in parameters)
+                            {
+                                string pName = "Type " + p.Definition.Name;
+                                string tempVal = "";
+                                if (!_parameterDictionary[category].Contains(pName))
+                                {
+                                    if (StorageType.String == p.StorageType)
+                                    {
+                                        tempVal = p.AsString();
+                                    }
+                                    else
+                                    {
+                                        tempVal = p.AsValueString();
+                                    }
 
-      if( null != folder_path
-        && 0 < folder_path.Length )
-      {
-        dlg.InitialDirectory = folder_path;
-      }
+                                    if (!string.IsNullOrEmpty(tempVal))
+                                    {
+                                        if (_parameterDictionary.ContainsKey(category))
+                                        {
+                                            if (!_parameterDictionary[category].Contains(pName))
+                                            {
+                                                _parameterDictionary[category].Add(pName);
+                                            }
+                                        }
+                                        else
+                                        {
+                                            parameterTypes.Add(pName);
+                                        }
+                                    }
+                                }
+                            }
+                            if (parameterTypes.Count > 0)
+                            {
+                                _parameterDictionary[category].AddRange(parameterTypes);
+                            }
+                        }
 
-      dlg.FileName = filename;
+                    } 
+                }
+            }
 
-      bool rc = DialogResult.OK == dlg.ShowDialog();
+            //CREATE FILTER UI
+            _filter = new ParameterFilter();
 
-      if( rc )
-      {
-        filename = Path.Combine( dlg.InitialDirectory, 
-          dlg.FileName );
+            _tabControl = new TabControl();
+            _tabControl.Size = new System.Drawing.Size(600, 375);
+            _tabControl.Location = new System.Drawing.Point(0, 55);
+            _tabControl.Anchor = ((System.Windows.Forms.AnchorStyles)((((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Bottom)
+                | System.Windows.Forms.AnchorStyles.Left)
+                | System.Windows.Forms.AnchorStyles.Right)));
 
-        folder_path = Path.GetDirectoryName( 
-          filename );
-      }
-      return rc;
-    }
-    #endregion // SelectFile
+            int j = 8;
 
-    public Result Execute(
-      ExternalCommandData commandData,
-      ref string message,
-      ElementSet elements )
-    {
-      UIApplication uiapp = commandData.Application;
-      UIDocument uidoc = uiapp.ActiveUIDocument;
-      Application app = uiapp.Application;
-      Document doc = uidoc.Document;
-
-      if( doc.ActiveView is View3D )
-      {
-        string filename = doc.PathName;
-        if( 0 == filename.Length )
-        {
-          filename = doc.Title;
+            // Populate the parameters as a checkbox in each tab
+            foreach (string c in _parameterDictionary.Keys)
+            {
+                //Create a checklist
+                CheckedListBox checkList = new CheckedListBox();
+
+                //set the properties of the checklist
+                checkList.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Top | System.Windows.Forms.AnchorStyles.Left | System.Windows.Forms.AnchorStyles.Right)));
+                checkList.FormattingEnabled = true;
+                checkList.HorizontalScrollbar = true;
+                checkList.Items.AddRange(_parameterDictionary[c].ToArray());
+                checkList.MultiColumn = true;
+                checkList.Size = new System.Drawing.Size(560, 360);
+                checkList.ColumnWidth = 200;
+                checkList.CheckOnClick = true;
+                checkList.TabIndex = j;
+                j++;
+
+                for (int i = 0; i <= (checkList.Items.Count - 1); i++)
+                {
+                    checkList.SetItemCheckState(i, CheckState.Checked);
+                }
+
+                //add a tab
+                TabPage tab = new TabPage(c);
+                tab.Name = c;
+
+                //attach the checklist to the tab
+                tab.Controls.Add(checkList);
+
+                // attach the tab to the tab control
+                _tabControl.TabPages.Add(tab);
+            }
+
+            // Attach the tab control to the filter form
+            _filter.Controls.Add(_tabControl);
+
+            // DISPLAY FILTER UI
+            _filter.ShowDialog();
+
+            // Loop thru each tab and get the parameters to export
+            foreach (TabPage tab in _tabControl.TabPages)
+            {
+                List<string> parametersToExport = new List<string>();
+                foreach (var checkedP in ((CheckedListBox)tab.Controls[0]).CheckedItems)
+                {
+                    parametersToExport.Add(checkedP.ToString());
+                }
+                _toExportDictionary.Add(tab.Name, parametersToExport);
+            }
         }
-        if( null == _output_folder_path )
+
+
+        #region SelectFile
+        /// <summary>
+        /// Store the last user selected output folder
+        /// in the current editing session.
+        /// </summary>
+        static string _output_folder_path = null;
+
+
+        /// <summary>
+        /// Return true is user selects and confirms
+        /// output file name and folder.
+        /// </summary>
+        static bool SelectFile(
+          ref string folder_path,
+          ref string filename)
         {
-          _output_folder_path = Path.GetDirectoryName(
-            filename );
+            SaveFileDialog dlg = new SaveFileDialog();
+
+            dlg.Title = "Select JSON Output File";
+            dlg.Filter = "JSON files|*.js";
+
+            if (null != folder_path
+              && 0 < folder_path.Length)
+            {
+                dlg.InitialDirectory = folder_path;
+            }
+
+            dlg.FileName = filename;
+
+            bool rc = DialogResult.OK == dlg.ShowDialog();
+
+            if (rc)
+            {
+                filename = Path.Combine(dlg.InitialDirectory,
+                  dlg.FileName);
+
+                folder_path = Path.GetDirectoryName(
+                  filename);
+            }
+            return rc;
         }
-        filename = Path.GetFileName( filename ) + ".js";
+        #endregion // SelectFile
 
-        if( SelectFile( ref _output_folder_path,
-          ref filename ) )
+        public Result Execute(
+          ExternalCommandData commandData,
+          ref string message,
+          ElementSet elements)
         {
-          filename = Path.Combine( _output_folder_path,
-            filename );
+            UIApplication uiapp = commandData.Application;
+            UIDocument uidoc = uiapp.ActiveUIDocument;
+            Autodesk.Revit.ApplicationServices.Application app = uiapp.Application;
+            Document doc = uidoc.Document;
+
+           
+
+            if (doc.ActiveView is View3D)
+            {
+                string filename = doc.PathName;
+                if (0 == filename.Length)
+                {
+                    filename = doc.Title;
+                }
+                if (null == _output_folder_path)
+                {
+                    //sometimes the command fails if the file is detached from central and not saved locally
+                    try
+                    {
+                        _output_folder_path = Path.GetDirectoryName(
+                          filename);
+                    }
+                    catch
+                    {
+                        TaskDialog.Show("Folder not found", "Please, save the file and run the command again");
+                        return Result.Failed;
+                    }
+                }
+
+                //Dialog to ask the user if they want to choose which parameters to export or just export them all
+                TaskDialog td = new TaskDialog("Ask user to filter parameters");
+                td.Title = "Filter parameters";
+                td.CommonButtons = TaskDialogCommonButtons.No | TaskDialogCommonButtons.Yes;
+                td.MainInstruction = "Do you want to filter the parameters of the objects to be exported?";
+                td.MainContent = "Click Yes and you will be able to select parameters for each category in the next window";
+                td.AllowCancellation = true;
+                td.VerificationText = "Check this to include type properties";
+                TaskDialogResult tdResult = td.Show();
+
+                if (td.WasVerificationChecked()) includeT = true;
+                else includeT = false;
+
+                if (tdResult == TaskDialogResult.Yes)
+                {
+                    // Filter the properties
+                    filterElementParameters(doc, includeT);
+                    _filterParameters = true;
+                    if (ParameterFilter.status == "cancelled")
+                    {
+                        ParameterFilter.status = "";
+                        return Result.Cancelled;
+                    }
+                }
+                else _filterParameters = false;
+
+
+                ViewOrientation3D vo = ((View3D)doc.ActiveView).GetOrientation();
+
+                // Save file
+                filename = Path.GetFileName(filename) + ".js";
+
+                if (SelectFile(ref _output_folder_path,
+                  ref filename))
+                {
+                    filename = Path.Combine(_output_folder_path,
+                      filename);
 
-          ExportView3D( doc.ActiveView as View3D,
-            filename );
+                    ExportView3D(doc.ActiveView as View3D,
+                      filename);
 
-          return Result.Succeeded;
+                    return Result.Succeeded;
+                }
+                return Result.Cancelled;
+            }
+            else
+            {
+                Util.ErrorMsg(
+                  "You must be in a 3D view to export.");
+            }
+            return Result.Failed;
         }
-        return Result.Cancelled;
-      }
-      else
-      {
-        Util.ErrorMsg( 
-          "You must be in a 3D view to export." );
-      }
-      return Result.Failed;
     }
-  }
 }
diff --git a/RvtVa3c/ParameterFilter.Designer.cs b/RvtVa3c/ParameterFilter.Designer.cs
new file mode 100644
index 0000000..8ca0f0a
--- /dev/null
+++ b/RvtVa3c/ParameterFilter.Designer.cs
@@ -0,0 +1,129 @@
+namespace RvtVa3c
+{
+    partial class ParameterFilter
+    {
+        /// <summary>
+        /// Required designer variable.
+        /// </summary>
+        private System.ComponentModel.IContainer components = null;
+
+        /// <summary>
+        /// Clean up any resources being used.
+        /// </summary>
+        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
+        protected override void Dispose(bool disposing)
+        {
+            if (disposing && (components != null))
+            {
+                components.Dispose();
+            }
+            base.Dispose(disposing);
+        }
+
+        #region Windows Form Designer generated code
+
+        /// <summary>
+        /// Required method for Designer support - do not modify
+        /// the contents of this method with the code editor.
+        /// </summary>
+        private void InitializeComponent()
+        {
+            this.checkUncheck = new System.Windows.Forms.Button();
+            this.export_button = new System.Windows.Forms.Button();
+            this.cancelButton = new System.Windows.Forms.Button();
+            this.Description = new System.Windows.Forms.Label();
+            this.checkBox1 = new System.Windows.Forms.CheckBox();
+            this.SuspendLayout();
+            // 
+            // checkUncheck
+            // 
+            this.checkUncheck.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)));
+            this.checkUncheck.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.checkUncheck.Location = new System.Drawing.Point(12, 447);
+            this.checkUncheck.Name = "checkUncheck";
+            this.checkUncheck.Size = new System.Drawing.Size(139, 33);
+            this.checkUncheck.TabIndex = 4;
+            this.checkUncheck.Text = "Check / Uncheck All";
+            this.checkUncheck.UseVisualStyleBackColor = true;
+            this.checkUncheck.Click += new System.EventHandler(this.checkUncheck_Click);
+            // 
+            // export_button
+            // 
+            this.export_button.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.export_button.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.export_button.Location = new System.Drawing.Point(395, 447);
+            this.export_button.Name = "export_button";
+            this.export_button.Size = new System.Drawing.Size(93, 33);
+            this.export_button.TabIndex = 5;
+            this.export_button.Text = "EXPORT";
+            this.export_button.UseVisualStyleBackColor = true;
+            this.export_button.Click += new System.EventHandler(this.export_button_Click);
+            // 
+            // cancelButton
+            // 
+            this.cancelButton.Anchor = ((System.Windows.Forms.AnchorStyles)((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Right)));
+            this.cancelButton.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.cancelButton.Location = new System.Drawing.Point(505, 447);
+            this.cancelButton.Name = "cancelButton";
+            this.cancelButton.Size = new System.Drawing.Size(87, 33);
+            this.cancelButton.TabIndex = 6;
+            this.cancelButton.Text = "CANCEL";
+            this.cancelButton.UseVisualStyleBackColor = true;
+            this.cancelButton.Click += new System.EventHandler(this.cancelButton_Click);
+            // 
+            // Description
+            // 
+            this.Description.Font = new System.Drawing.Font("Arial", 8.25F, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, ((byte)(0)));
+            this.Description.Location = new System.Drawing.Point(9, 9);
+            this.Description.Name = "Description";
+            this.Description.Size = new System.Drawing.Size(398, 45);
+            this.Description.TabIndex = 7;
+            this.Description.Text = "Select which parameters should be included with each category";
+            // 
+            // checkBox1
+            // 
+            this.checkBox1.AutoSize = true;
+            this.checkBox1.Checked = true;
+            this.checkBox1.CheckState = System.Windows.Forms.CheckState.Checked;
+            this.checkBox1.Location = new System.Drawing.Point(159, 455);
+            this.checkBox1.Name = "checkBox1";
+            this.checkBox1.Size = new System.Drawing.Size(188, 17);
+            this.checkBox1.TabIndex = 8;
+            this.checkBox1.Text = "Check / Uncheck current tab only";
+            this.checkBox1.UseVisualStyleBackColor = true;
+            this.checkBox1.CheckedChanged += new System.EventHandler(this.checkBox1_CheckedChanged);
+            // 
+            // ParameterFilter
+            // 
+            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
+            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
+            this.BackColor = System.Drawing.SystemColors.ButtonHighlight;
+            this.ClientSize = new System.Drawing.Size(604, 492);
+            this.ControlBox = false;
+            this.Controls.Add(this.checkBox1);
+            this.Controls.Add(this.cancelButton);
+            this.Controls.Add(this.export_button);
+            this.Controls.Add(this.checkUncheck);
+            this.Controls.Add(this.Description);
+            this.MaximumSize = new System.Drawing.Size(900, 530);
+            this.MinimumSize = new System.Drawing.Size(620, 530);
+            this.Name = "ParameterFilter";
+            this.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen;
+            this.Text = "Parameter Filter";
+            this.ResumeLayout(false);
+            this.PerformLayout();
+
+        }
+
+        #endregion
+
+        private System.Windows.Forms.Button checkUncheck;
+        private System.Windows.Forms.Button export_button;
+        private System.Windows.Forms.Button cancelButton;
+        private System.Windows.Forms.Label Description;
+        private System.Windows.Forms.CheckBox checkBox1;
+
+
+
+    }
+}
\ No newline at end of file
diff --git a/RvtVa3c/ParameterFilter.cs b/RvtVa3c/ParameterFilter.cs
new file mode 100644
index 0000000..ec1ddfb
--- /dev/null
+++ b/RvtVa3c/ParameterFilter.cs
@@ -0,0 +1,99 @@
+using System;
+using System.Collections.Generic;
+using System.ComponentModel;
+using System.Data;
+using System.Drawing;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Windows.Forms;
+
+namespace RvtVa3c
+{
+    public partial class ParameterFilter : Form
+    {
+        public ParameterFilter()
+        {
+            InitializeComponent();
+        }
+
+
+        public static string status = "";
+        private bool changeAll = false;
+        /// <summary>
+        /// Function to check or uncheck all the checkboxes in a tab
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        private void checkUncheck_Click(object sender, EventArgs e)
+        {
+            
+            int index = Command._tabControl.SelectedIndex;
+            CheckedListBox currentCheckList = new CheckedListBox();
+            if (!changeAll)
+            {
+                currentCheckList = (CheckedListBox)((TabPage)(Command._tabControl.GetControl(index))).Controls[0];
+
+                bool areAllChecked = true;
+                if (currentCheckList.CheckedItems.Count < currentCheckList.Items.Count) areAllChecked = false;
+                checkUncheckBoxes(currentCheckList, areAllChecked);
+            }
+            else
+            {
+                List<CheckedListBox> allCheckLists = new List<CheckedListBox>();
+                bool areAllChecked = true;
+                
+                foreach (TabPage tab in Command._tabControl.TabPages)
+                {
+                    currentCheckList = (CheckedListBox) tab.Controls[0];
+                    if (currentCheckList.CheckedItems.Count < currentCheckList.Items.Count)
+                    {
+                        areAllChecked = false;
+                        break;
+                    }
+                }
+
+                foreach (TabPage tab in Command._tabControl.TabPages)
+                {
+                    currentCheckList = (CheckedListBox)tab.Controls[0];
+                    checkUncheckBoxes(currentCheckList, areAllChecked);
+                }
+            }
+        }
+
+        private void export_button_Click(object sender, EventArgs e)
+        {
+            this.Close();
+        }
+
+        private void cancelButton_Click(object sender, EventArgs e)
+        {
+            this.Close();
+            status = "cancelled";
+        }
+
+        private void checkBox1_CheckedChanged(object sender, EventArgs e)
+        {
+            if (checkBox1.Checked) changeAll = false;
+            else changeAll = true;
+        }
+
+        private void checkUncheckBoxes(CheckedListBox currentCheckList, bool areAllChecked)
+        {
+            if (!areAllChecked)
+            {
+                for (int i = 0; i <= (currentCheckList.Items.Count - 1); i++)
+                {
+                    currentCheckList.SetItemCheckState(i, CheckState.Checked);
+                }
+            }
+            else
+            {
+                for (int i = 0; i <= (currentCheckList.Items.Count - 1); i++)
+                {
+                    currentCheckList.SetItemCheckState(i, CheckState.Unchecked);
+                }
+            }
+        }
+    }
+}
diff --git a/RvtVa3c/ParameterFilter.resx b/RvtVa3c/ParameterFilter.resx
new file mode 100644
index 0000000..1af7de1
--- /dev/null
+++ b/RvtVa3c/ParameterFilter.resx
@@ -0,0 +1,120 @@
+<?xml version="1.0" encoding="utf-8"?>
+<root>
+  <!-- 
+    Microsoft ResX Schema 
+    
+    Version 2.0
+    
+    The primary goals of this format is to allow a simple XML format 
+    that is mostly human readable. The generation and parsing of the 
+    various data types are done through the TypeConverter classes 
+    associated with the data types.
+    
+    Example:
+    
+    ... ado.net/XML headers & schema ...
+    <resheader name="resmimetype">text/microsoft-resx</resheader>
+    <resheader name="version">2.0</resheader>
+    <resheader name="reader">System.Resources.ResXResourceReader, System.Windows.Forms, ...</resheader>
+    <resheader name="writer">System.Resources.ResXResourceWriter, System.Windows.Forms, ...</resheader>
+    <data name="Name1"><value>this is my long string</value><comment>this is a comment</comment></data>
+    <data name="Color1" type="System.Drawing.Color, System.Drawing">Blue</data>
+    <data name="Bitmap1" mimetype="application/x-microsoft.net.object.binary.base64">
+        <value>[base64 mime encoded serialized .NET Framework object]</value>
+    </data>
+    <data name="Icon1" type="System.Drawing.Icon, System.Drawing" mimetype="application/x-microsoft.net.object.bytearray.base64">
+        <value>[base64 mime encoded string representing a byte array form of the .NET Framework object]</value>
+        <comment>This is a comment</comment>
+    </data>
+                
+    There are any number of "resheader" rows that contain simple 
+    name/value pairs.
+    
+    Each data row contains a name, and value. The row also contains a 
+    type or mimetype. Type corresponds to a .NET class that support 
+    text/value conversion through the TypeConverter architecture. 
+    Classes that don't support this are serialized and stored with the 
+    mimetype set.
+    
+    The mimetype is used for serialized objects, and tells the 
+    ResXResourceReader how to depersist the object. This is currently not 
+    extensible. For a given mimetype the value must be set accordingly:
+    
+    Note - application/x-microsoft.net.object.binary.base64 is the format 
+    that the ResXResourceWriter will generate, however the reader can 
+    read any of the formats listed below.
+    
+    mimetype: application/x-microsoft.net.object.binary.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Binary.BinaryFormatter
+            : and then encoded with base64 encoding.
+    
+    mimetype: application/x-microsoft.net.object.soap.base64
+    value   : The object must be serialized with 
+            : System.Runtime.Serialization.Formatters.Soap.SoapFormatter
+            : and then encoded with base64 encoding.
+
+    mimetype: application/x-microsoft.net.object.bytearray.base64
+    value   : The object must be serialized into a byte array 
+            : using a System.ComponentModel.TypeConverter
+            : and then encoded with base64 encoding.
+    -->
+  <xsd:schema id="root" xmlns="" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:msdata="urn:schemas-microsoft-com:xml-msdata">
+    <xsd:import namespace="http://www.w3.org/XML/1998/namespace" />
+    <xsd:element name="root" msdata:IsDataSet="true">
+      <xsd:complexType>
+        <xsd:choice maxOccurs="unbounded">
+          <xsd:element name="metadata">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" />
+              </xsd:sequence>
+              <xsd:attribute name="name" use="required" type="xsd:string" />
+              <xsd:attribute name="type" type="xsd:string" />
+              <xsd:attribute name="mimetype" type="xsd:string" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="assembly">
+            <xsd:complexType>
+              <xsd:attribute name="alias" type="xsd:string" />
+              <xsd:attribute name="name" type="xsd:string" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="data">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+                <xsd:element name="comment" type="xsd:string" minOccurs="0" msdata:Ordinal="2" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" msdata:Ordinal="1" />
+              <xsd:attribute name="type" type="xsd:string" msdata:Ordinal="3" />
+              <xsd:attribute name="mimetype" type="xsd:string" msdata:Ordinal="4" />
+              <xsd:attribute ref="xml:space" />
+            </xsd:complexType>
+          </xsd:element>
+          <xsd:element name="resheader">
+            <xsd:complexType>
+              <xsd:sequence>
+                <xsd:element name="value" type="xsd:string" minOccurs="0" msdata:Ordinal="1" />
+              </xsd:sequence>
+              <xsd:attribute name="name" type="xsd:string" use="required" />
+            </xsd:complexType>
+          </xsd:element>
+        </xsd:choice>
+      </xsd:complexType>
+    </xsd:element>
+  </xsd:schema>
+  <resheader name="resmimetype">
+    <value>text/microsoft-resx</value>
+  </resheader>
+  <resheader name="version">
+    <value>2.0</value>
+  </resheader>
+  <resheader name="reader">
+    <value>System.Resources.ResXResourceReader, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+  <resheader name="writer">
+    <value>System.Resources.ResXResourceWriter, System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089</value>
+  </resheader>
+</root>
\ No newline at end of file
diff --git a/RvtVa3c/RvtVa3c.csproj b/RvtVa3c/RvtVa3c.csproj
index a6546aa..fbd8472 100644
--- a/RvtVa3c/RvtVa3c.csproj
+++ b/RvtVa3c/RvtVa3c.csproj
@@ -48,6 +48,8 @@
     <Reference Include="Newtonsoft.Json">
       <HintPath>packages\Newtonsoft.Json.dll</HintPath>
     </Reference>
+    <Reference Include="PresentationCore" />
+    <Reference Include="PresentationFramework" />
     <Reference Include="RevitAPI">
       <HintPath>$(ProgramW6432)\Autodesk\Revit 2015\RevitAPI.dll</HintPath>
       <Private>False</Private>
@@ -57,6 +59,8 @@
       <Private>False</Private>
     </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Data" />
+    <Reference Include="System.Drawing" />
     <Reference Include="System.Runtime.Serialization" />
     <Reference Include="System.Windows.Forms" />
     <Reference Include="System.XML" />
@@ -65,6 +69,12 @@
   <ItemGroup>
     <Compile Include="App.cs" />
     <Compile Include="Command.cs" />
+    <Compile Include="ParameterFilter.cs">
+      <SubType>Form</SubType>
+    </Compile>
+    <Compile Include="ParameterFilter.Designer.cs">
+      <DependentUpon>ParameterFilter.cs</DependentUpon>
+    </Compile>
     <Compile Include="Properties\AssemblyInfo.cs" />
     <Compile Include="UserSettings.cs" />
     <Compile Include="Util.cs" />
@@ -76,6 +86,11 @@
     <None Include="packages.config" />
     <None Include="RvtVa3c.addin" />
   </ItemGroup>
+  <ItemGroup>
+    <EmbeddedResource Include="ParameterFilter.resx">
+      <DependentUpon>ParameterFilter.cs</DependentUpon>
+    </EmbeddedResource>
+  </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
   <Target Name="AfterClean">
     <Delete Files="$(AppData)\Autodesk\REVIT\Addins\2015\RvtVa3c.addin" />
diff --git a/RvtVa3c/Util.cs b/RvtVa3c/Util.cs
index f0c48fb..5aebba0 100644
--- a/RvtVa3c/Util.cs
+++ b/RvtVa3c/Util.cs
@@ -1,5 +1,6 @@
 #region Namespaces
 using System;
+using Autodesk.Revit.UI;
 using System.Collections.Generic;
 using System.Diagnostics;
 using Autodesk.Revit.DB;
@@ -8,217 +9,311 @@
 
 namespace RvtVa3c
 {
-  class Util
-  {
-    const string _caption = "vA3C";
-
-    /// <summary>
-    /// Display an error message to the user.
-    /// </summary>
-    public static void ErrorMsg( string msg )
+    class Util
     {
-      Debug.WriteLine( msg );
-      WinForms.MessageBox.Show( msg,
-        _caption,
-        WinForms.MessageBoxButtons.OK,
-        WinForms.MessageBoxIcon.Error );
-    }
-
-    /// <summary>
-    /// Return a string for a real number
-    /// formatted to two decimal places.
-    /// </summary>
-    public static string RealString( double a )
-    {
-      return a.ToString( "0.##" );
-    }
+        const string _caption = "vA3C";
 
-    /// <summary>
-    /// Return a string for an XYZ point
-    /// or vector with its coordinates
-    /// formatted to two decimal places.
-    /// </summary>
-    public static string PointString( XYZ p )
-    {
-      return string.Format( "({0},{1},{2})",
-        RealString( p.X ),
-        RealString( p.Y ),
-        RealString( p.Z ) );
-    }
+        /// <summary>
+        /// Display an error message to the user.
+        /// </summary>
+        public static void ErrorMsg(string msg)
+        {
+            Debug.WriteLine(msg);
+            WinForms.MessageBox.Show(msg,
+              _caption,
+              WinForms.MessageBoxButtons.OK,
+              WinForms.MessageBoxIcon.Error);
+        }
 
-    /// <summary>
-    /// Return an integer value for a Revit Color.
-    /// </summary>
-    public static int ColorToInt( Color color )
-    {
-      return ( (int) color.Red ) << 16
-        | ( (int) color.Green ) << 8
-        | (int) color.Blue;
-    }
+        /// <summary>
+        /// Return a string for a real number
+        /// formatted to two decimal places.
+        /// </summary>
+        public static string RealString(double a)
+        {
+            return a.ToString("0.##");
+        }
 
-    /// <summary>
-    /// Extract a true or false value from the given
-    /// string, accepting yes/no, Y/N, true/false, T/F
-    /// and 1/0. We are extremely tolerant, i.e., any
-    /// value starting with one of the characters y, n,
-    /// t or f is also accepted. Return false if no 
-    /// valid Boolean value can be extracted.
-    /// </summary>
-    public static bool GetTrueOrFalse(
-      string s,
-      out bool val )
-    {
-      val = false;
-
-      if( s.Equals( Boolean.TrueString,
-        StringComparison.OrdinalIgnoreCase ) )
-      {
-        val = true;
-        return true;
-      }
-      if( s.Equals( Boolean.FalseString,
-        StringComparison.OrdinalIgnoreCase ) )
-      {
-        return true;
-      }
-      if( s.Equals( "1" ) )
-      {
-        val = true;
-        return true;
-      }
-      if( s.Equals( "0" ) )
-      {
-        return true;
-      }
-      s = s.ToLower();
-
-      if( 't' == s[0] || 'y' == s[0] )
-      {
-        val = true;
-        return true;
-      }
-      if( 'f' == s[0] || 'n' == s[0] )
-      {
-        return true;
-      }
-      return false;
-    }
+        /// <summary>
+        /// Return a string for an XYZ point
+        /// or vector with its coordinates
+        /// formatted to two decimal places.
+        /// </summary>
+        public static string PointString(XYZ p)
+        {
+            return string.Format("({0},{1},{2})",
+              RealString(p.X),
+              RealString(p.Y),
+              RealString(p.Z));
+        }
 
-    /// <summary>
-    /// Return a string describing the given element:
-    /// .NET type name,
-    /// category name,
-    /// family and symbol name for a family instance,
-    /// element id and element name.
-    /// </summary>
-    public static string ElementDescription(
-      Element e )
-    {
-      if( null == e )
-      {
-        return "<null>";
-      }
+        /// <summary>
+        /// Return an integer value for a Revit Color.
+        /// </summary>
+        public static int ColorToInt(Color color)
+        {
+            return ((int)color.Red) << 16
+              | ((int)color.Green) << 8
+              | (int)color.Blue;
+        }
 
-      // For a wall, the element name equals the
-      // wall type name, which is equivalent to the
-      // family name ...
+        /// <summary>
+        /// Extract a true or false value from the given
+        /// string, accepting yes/no, Y/N, true/false, T/F
+        /// and 1/0. We are extremely tolerant, i.e., any
+        /// value starting with one of the characters y, n,
+        /// t or f is also accepted. Return false if no 
+        /// valid Boolean value can be extracted.
+        /// </summary>
+        public static bool GetTrueOrFalse(
+          string s,
+          out bool val)
+        {
+            val = false;
 
-      FamilyInstance fi = e as FamilyInstance;
+            if (s.Equals(Boolean.TrueString,
+              StringComparison.OrdinalIgnoreCase))
+            {
+                val = true;
+                return true;
+            }
+            if (s.Equals(Boolean.FalseString,
+              StringComparison.OrdinalIgnoreCase))
+            {
+                return true;
+            }
+            if (s.Equals("1"))
+            {
+                val = true;
+                return true;
+            }
+            if (s.Equals("0"))
+            {
+                return true;
+            }
+            s = s.ToLower();
 
-      string typeName = e.GetType().Name;
+            if ('t' == s[0] || 'y' == s[0])
+            {
+                val = true;
+                return true;
+            }
+            if ('f' == s[0] || 'n' == s[0])
+            {
+                return true;
+            }
+            return false;
+        }
 
-      string categoryName = ( null == e.Category )
-        ? string.Empty
-        : e.Category.Name + " ";
+        /// <summary>
+        /// Return a string describing the given element:
+        /// .NET type name,
+        /// category name,
+        /// family and symbol name for a family instance,
+        /// element id and element name.
+        /// </summary>
+        public static string ElementDescription(
+          Element e)
+        {
+            if (null == e)
+            {
+                return "<null>";
+            }
 
-      string familyName = ( null == fi )
-        ? string.Empty
-        : fi.Symbol.Family.Name + " ";
+            // For a wall, the element name equals the
+            // wall type name, which is equivalent to the
+            // family name ...
 
-      string symbolName = ( null == fi
-        || e.Name.Equals( fi.Symbol.Name ) )
-          ? string.Empty
-          : fi.Symbol.Name + " ";
+            FamilyInstance fi = e as FamilyInstance;
 
-      return string.Format( "{0} {1}{2}{3}<{4} {5}>",
-        typeName, categoryName, familyName,
-        symbolName, e.Id.IntegerValue, e.Name );
-    }
+            string typeName = e.GetType().Name;
 
-    /// <summary>
-    /// Return a dictionary of all the given 
-    /// element parameter names and values.
-    /// </summary>
-    public static Dictionary<string, string>
-      GetElementProperties(
-        Element e,
-        bool includeType )
-    {
-      IList<Parameter> parameters
-        = e.GetOrderedParameters();
+            string categoryName = (null == e.Category)
+              ? string.Empty
+              : e.Category.Name + " ";
 
-      Dictionary<string, string> a
-        = new Dictionary<string, string>(
-          parameters.Count );
+            string familyName = (null == fi)
+              ? string.Empty
+              : fi.Symbol.Family.Name + " ";
 
-      string key;
-      string val;
+            string symbolName = (null == fi
+              || e.Name.Equals(fi.Symbol.Name))
+                ? string.Empty
+                : fi.Symbol.Name + " ";
 
-      foreach( Parameter p in parameters )
-      {
-        key = p.Definition.Name;
+            return string.Format("{0} {1}{2}{3}<{4} {5}>",
+              typeName, categoryName, familyName,
+              symbolName, e.Id.IntegerValue, e.Name);
+        }
 
-        if( !a.ContainsKey( key ) )
+        /// <summary>
+        /// Return a dictionary of all the given 
+        /// element parameter names and values.
+        /// </summary>
+        public static Dictionary<string, string>
+          GetElementProperties(
+            Element e,
+            bool includeType)
         {
-          if( StorageType.String == p.StorageType )
-          {
-            val = p.AsString();
-          }
-          else
-          {
-            val = p.AsValueString();
-          }
-
-          if( !string.IsNullOrEmpty( val ) )
-          {
-            a.Add( key, val );
-          }
+            IList<Parameter> parameters
+              = e.GetOrderedParameters();
+
+            Dictionary<string, string> a
+              = new Dictionary<string, string>(
+                parameters.Count);
+
+
+
+            string key;
+            string val;
+
+
+
+            foreach (Parameter p in parameters)
+            {
+                key = p.Definition.Name;
+
+                if (!a.ContainsKey(key))
+                {
+                    if (StorageType.String == p.StorageType)
+                    {
+                        val = p.AsString();
+                    }
+                    else
+                    {
+                        val = p.AsValueString();
+                    }
+
+                    if (!string.IsNullOrEmpty(val))
+                    {
+                        a.Add(key, val);
+                    }
+                }
+            }
+
+            if (includeType)
+            {
+                ElementId idType = e.GetTypeId();
+
+                if (ElementId.InvalidElementId != idType)
+                {
+                    Document doc = e.Document;
+                    Element typ = doc.GetElement(idType);
+                    parameters = typ.GetOrderedParameters();
+                    foreach (Parameter p in parameters)
+                    {
+                        key = "Type " + p.Definition.Name;
+
+                        if (!a.ContainsKey(key))
+                        {
+                            if (StorageType.String == p.StorageType)
+                            {
+                                val = p.AsString();
+                            }
+                            else
+                            {
+                                val = p.AsValueString();
+                            }
+
+                            if (!string.IsNullOrEmpty(val))
+                            {
+                                a.Add(key, val);
+                            }
+                        }
+                    }
+                }
+            }
+            return a;
         }
-      }
 
-      if( includeType )
-      {
-        ElementId idType = e.GetTypeId();
 
-        if( ElementId.InvalidElementId != idType )
+        /// <summary>
+        /// Return a dictionary of all the given 
+        /// element parameter names and values.
+        /// </summary>
+        public static Dictionary<string, string>
+          GetElementFilteredProperties(
+            Element e,
+            bool includeType)
         {
-          Document doc = e.Document;
-          Element typ = doc.GetElement( idType );
-          parameters = typ.GetOrderedParameters();
-          foreach( Parameter p in parameters )
-          {
-            key = "Type " + p.Definition.Name;
-
-            if( !a.ContainsKey( key ) )
+            IList<Parameter> parameters
+              = e.GetOrderedParameters();
+
+            Dictionary<string, string> a
+              = new Dictionary<string, string>(
+                parameters.Count);
+
+            string key;
+            string val;
+            string cat = e.Category.Name;
+            //making sure that the file has a tab for that category
+            if (Command._toExportDictionary.ContainsKey(cat))
             {
-              if( StorageType.String == p.StorageType )
-              {
-                val = p.AsString();
-              }
-              else
-              {
-                val = p.AsValueString();
-              }
-
-              if( !string.IsNullOrEmpty( val ) )
-              {
-                a.Add( key, val );
-              }
+                foreach (Parameter p in parameters)
+                {
+                    key = p.Definition.Name;
+
+                    //checking if the property has been checked
+                    if (Command._toExportDictionary[cat].Contains(key))
+                    {
+                        if (!a.ContainsKey(key))
+                        {
+                            if (StorageType.String == p.StorageType)
+                            {
+                                val = p.AsString();
+                            }
+                            else
+                            {
+                                val = p.AsValueString();
+                            }
+
+                            if (!string.IsNullOrEmpty(val))
+                            {
+                                a.Add(key, val);
+                            }
+                        }
+                    }
+                }
+
+                if (includeType)
+                {
+                    ElementId idType = e.GetTypeId();
+
+                    if (ElementId.InvalidElementId != idType)
+                    {
+                        Document doc = e.Document;
+                        Element typ = doc.GetElement(idType);
+                        parameters = typ.GetOrderedParameters();
+                        
+                        foreach (Parameter p in parameters)
+                        {
+                            key = "Type " + p.Definition.Name;
+
+                            //checking if the property has been checked
+                            if (Command._toExportDictionary[cat].Contains(key))
+                            {
+                                if (!a.ContainsKey(key))
+                                {
+                                    if (StorageType.String == p.StorageType)
+                                    {
+                                        val = p.AsString();
+                                    }
+                                    else
+                                    {
+                                        val = p.AsValueString();
+                                    }
+
+                                    if (!string.IsNullOrEmpty(val))
+                                    {
+                                        a.Add(key, val);
+                                    }
+                                } 
+                            }
+                        }
+                    }
+                }
             }
-          }
+            return a;
         }
-      }
-      return a;
     }
-  }
 }