Kevin,
Here's some sample code(very simple):
Declare Integer FindWindow in Win32API Integer,String
wclass=0
winname="Microsoft Visual Foxpro"
apphand=FindWindow(wclass ,winname)
IF apphand=0
* no other instances found
>Hi
>
>I need an app to only be run once at one time.
>
>What's the best way to detect if a VFP app is already running ?
>
>Thanks
>Kev