Button Stopped Working

I have a button downloaded from this forum which I quite like. The function is view two images together in the image viewer. I also have it on my laptop and it works great, but it doesn't do anything but flash briefly in my PC. Don't have a clue what's wrong. Here is the text:

'This script will take TWO selected pictures and display them next to each other in separate imstances of the DOpus standalone viewer
'To work efficiently the viewer toolbar should contain a button called CLOSE with close every instance of the viewer and returns to the active Opus Lister

Function OnClick(ByRef clickData) 
   If clickData.func.sourcetab.selected_files.count <> 2 Then
      Msgbox "You MUST Select TWO Files and ONLY two files",16, "FILE SELECTION ERROR"
	  		ClickData.Func.Command.AddLine("Select NONE")
			ClickData.Func.command.Run
	  Exit Function
	  End If
ClipString = ""
blogbo = pathbo
   For Each SelectedItem In ClickData.Func.sourcetab.Selected
         dato = SelectedItem.create
         ClipString = SelectedItem.name_stem
		 exto = SelectedItem.ext
		 pathbo = selectedItem.path & "\" & ClipString & exto
blogbo = pathbo + ";" + blogbo
   Next   
   'now extract the filenames of the pictures
totchar = Len(blogbo) 
pos = InStr(1, blogbo, ";", vbTextCompare)
pos = pos -1
LResult = Left(blogbo,pos)
firstvar = totchar - pos
firstvar = firstvar-1
Rresult = Right(blogbo,firstvar)
totchar = Len(Rresult)
totchar = (totchar-1)
Rresult = Left(Rresult,totchar)
'Now display the images in the standalone viewer
		ClickData.Func.Command.AddLine("Select NONE")
        ClickData.Func.Command.AddLine("Show """ & LResult & """ POS 165,0  SIZE 650,1050 NOUSEEXISTING")
	    'ClickData.Func.command.Run
        ClickData.Func.Command.AddLine("Show """ & RResult & """ POS 800,0 SIZE 650,1050 NOUSEEXISTING")
  		ClickData.Func.command.Run

		End Function

The best thing to do is find the original thread for the button and ask in there, if there isn't already an updated version.