An ID that represents the dialog that has been displayed. 
   Namespace:   Autodesk.Revit.UI.Events  
  Assembly:   RevitAPIUI  (in RevitAPIUI.dll) Version: 2015.0.0.0 (2015.0.0.0) 
Syntax
Remarks
 Use this ID within your application to key suitable responses for the dialog. Note: this id is not guaranteed to remain stable for different builds of Autodesk Revit.