OS Dependent Logoff/Logon Script run via GPO

Option Explicit
Dim objItem, colItems, objWMIService, strComputer, objShell
strComputer = "."
Set objShell = CreateObject("WScript.Shell")
Set objWMIService = GetObject("winmgmts:\" & strComputer & "rootcimv2")
Set colItems = objWMIService.ExecQuery("Select * from Win32_OperatingSystem",,48)
For Each objItem in colItems
                If InStr(objItem.Caption,"2000") Then
                                'Add your line here for 2000
                                objShell.Run "regedit", 1, True
                End If
    		If InStr(LCase(objItem.Caption),Lcase("XP")) Then
                                'Add your command line here for 2000
                                objShell.Run "calc", 1, True
                End If
		If InStr(LCase(objItem.Caption),Lcase("2003")) Then
                                'Add your command line here for 2000
                                objShell.Run "notepad", 1, True
                End If
Next