>Here is the code I use, posted by someone else here long ago.
>
>

>DECLARE INTEGER CreateEvent IN WIN32API ;
>   INTEGER lpEventAttributes, ;
>   SHORT bManualReset, ;
>   SHORT bInitialState, ;
>   STRING @ lpName
>DECLARE INTEGER GetLastError IN Win32API
>DECLARE CloseHandle IN Win32API INTEGER hObject
>nEh = CreateEvent(0,0,1, PROGRAM(0) + '.EVENT')
>IF GetLastError() = 183 OR nEh = 0
>   *  There's an instance running already (183) or the Event can't be defined
>   *  So don't do it;  do release the handle, since it's harmless and should
>   *  be done rather than relying on Windows to clean up after itself
>   =CloseHandle(nEh)
>   QUIT
>ENDIF
>

>
>Bob
>

That's the late Ed Rauh's code.