Wow....! many thanks to all of you who have contributed to helping. In the end I have used a combination of your scripts to form the following. I hope you don't mind

Allen, Richard and Mart many thanks for your help

$wmiColl = GetObject("WinMgmts:root/cimv2").ExecQuery("Select * FROM Win32_DesktopMonitor")
For Each $wmiObj In $wmiColl
Select
Case $wmiObj.DeviceID = "DesktopMonitor1"
$screenres1 = CSTR($wmiObj.ScreenWidth) + "x" + CSTR($wmiObj.ScreenHeight)
Case $wmiObj.DeviceID = "DesktopMonitor2"
$screenres2 = CSTR($wmiObj.ScreenWidth) + "x" + CSTR($wmiObj.ScreenHeight)
EndSelect
Next

select
case $screenres1 = "1024x768"
;do stuff 1024
? "do stuff 1024 X 768 "
case $screenres1 = "800x600"
;do stuff 800
? "do stuff 800 X 600"
case 1
; Must be using some other resolution
endselect


select
case $screenres2 = "1024x768"
;do stuff 1024
? "do stuff 1024 X 768"
case $screenres2 = "800x600"
;do stuff 800
? "do stuff 800 X 600"
case 1
; Must be using some other resolution
endselect