lcformcaption = _SCREEN.Caption _SCREEN.Caption = "" * Use only one of the next two lines. SET PROCEDURE TO Mutex ADDITIVE && if in a prg SET CLASSLIB TO Mutex ADDITIVE && if in a VCX oMutex = CREATEOBJECT('Mutex', lcformcaption) IF oMutex.nMutexErr # ERROR_ALREADY_EXISTS * Your normal setup code here. (DO MYMENU.MPR, READ EVENTS, etc.) ELSE * If we hit this line, the other instance is displayed * and the current one released oMutex.DisplayInstance ENDIFDoes this help?