LPARAMETERS lcWindowName,lcSimpleAppName

** check to see if app is already open
DECLARE INTEGER FindWindow IN Win32API STRING lpClassName, STRING lpWindowName
DECLARE INTEGER IsIconic IN Win32api INTEGER
DECLARE ShowWindow IN Win32api INTEGER,INTEGER
DECLARE SetForegroundWindow IN Win32api INTEGER

nWinHandle = FindWindow(.NULL., lcWindowName)

*Returns 0 if it can't find "YourApp" as a window title,
*otherwise it returns a handle > 0
IF nWinHandle <> 0
	llFound=.T.
	MESSAGEBOX('A current session of '+ALLTRIM(lcSimpleAppName)+' is already in use.'+CHR(13)+CHR(10)+;
				'Only one session of '+ALLTRIM(lcSimpleAppName)+' can be used at a time.',0+64+0,_screen.Caption)
	IF IsIconic(nWinHandle) = 1
		ShowWindow(nWinHandle,4)
	ENDIF
	*Wait Wind "App is already running."+ CHR(13) + ;
	* "Switching to establish session." Timeout 2
	SetForegroundWindow(nWinHandle)
	QUIT
ENDIF