public void RevitLinksInfo()
		{
			UIDocument uidoc = this.ActiveUIDocument;
			Document doc = uidoc.Document;
			
			//select all the link instances
			FilteredElementCollector collector = new FilteredElementCollector(doc);
			collector.OfClass(typeof(RevitLinkInstance));
			
			//create a string to store the results
			System.Text.StringBuilder linkedDocs = new System.Text.StringBuilder();
			
			
			
	    foreach (Element elem in collector)
	    {
	    	try{
	    			//link instance
	    	        RevitLinkInstance instance = elem as RevitLinkInstance;
	    	        
	    	        //link type
	    	        ElementId rvtLinkTypeId = instance.GetTypeId();
	    	        RevitLinkType rvtLinkType = doc.GetElement(rvtLinkTypeId) as RevitLinkType;
	    	        
	    	        //Loaded/Unloaded/Locally Unloaded
	    	        string linkStatus = rvtLinkType.GetExternalFileReference().GetLinkedFileStatus().ToString();
	    	        
	    	        //Overlay or Attachment
	    	        Parameter referenceType = rvtLinkType.get_Parameter(BuiltInParameter.RVT_LINK_REFERENCE_TYPE);
	    	        
	    	        //Get File Path
	    	        ExternalFileReference externalLink = rvtLinkType.GetExternalFileReference();
	    	        string path = ModelPathUtils.ConvertModelPathToUserVisiblePath(externalLink.GetAbsolutePath());
	    	        

	    	        linkedDocs.AppendLine(String.Format("{0},{1},{2},{3},{4} ",rvtLinkType.Name,linkStatus,referenceType.AsValueString(),rvtLinkType.PathType.ToString(), path));
	    	        
	    	}
	    	catch(Exception ex){
	    		TaskDialog.Show("error", ex.Message);
	    	}
		}
    
//        TaskDialog.Show("Revit Links in Document", linkedDocs.ToString());

            using (System.IO.StreamWriter sw = new System.IO.StreamWriter(@"C:\Temp\RevitLinks.txt"))
            {

            	sw.WriteLine(linkedDocs);

            }
	
	TaskDialog.Show("Done", "The file has been saved to C:\\Temp\\RevitLinks.txt");
		}