*----------------------- Usage Section --------------------------
*)  Description: Use the Windows API to force a true screen lock.
* ...........: Calling this lock function with a handle of 0 unlocks all locked windows
*--------------------- Maintenance Section ----------------------
*   Change Log:
*       CREATED 	06/03/2005 - Marcia Akins
*		MODIFIED
*----------------------------------------------------------------
lparameters tlLock
local array laJunk[1]
local lnHWnd, lnRes
**********************************************************
*** Check that the library has been set up and open it if not already done.
**********************************************************
lnRes = adlls( laJunk )
if m.lnRes = 0 or  not ( ascan( laJunk, 'LockWindowUpdate', 1, -1, 1, 15 ) > 0)
*** We don't have the function available
	declare integer LockWindowUpdate in Win32API integer nHandle
endif
*** Now set the Handle to lock according to the parameter
lnHWnd = iif( m.tlLock, thisform.hwnd, 0 )
*** And call the function
LockWindowUpdate( m.lnHWnd )
return