You'll need to check for event source like so
SuperStrict Local MyWindow:TGadget=CreateWindow("Main Window", 200,200,320,240) Local AboutWindow:TGadget=CreateWindow("About Window",250,250,200,100,MyWindow) Repeat WaitEvent() Select EventID() Case EVENT_WINDOWCLOSE Select EventSource() Case AboutWindow FreeGadget AboutWindow Case Mywindow End End Select End Select Forever