Can anybody help?

I am writing a Vb.Net "AddIn" for Solidworks.

I need, for testing purposes, to show the sheet properties dialog box thus:

Here is my code so far.....

Imports System.Runtime.InteropServices

Imports SolidWorks.Interop.sldworks

Imports SolidWorks.Interop.swcommands

Imports SolidWorks.Interop.swconst

Module Module10
   Sub DisplayProperties()
       Dim swApp As OBJECT

       swApp = Marshal.GetActiveObject("SldWorks.Application")

       swApp.RunCommand(swCommands_e.swCommands_Properties, "")
   End Sub
End Module

Does anybody know what I am doing wrong as I cannot get the code to show the sheet properties, and can you correct the code for me?

Many thanks in advance!

Darren