If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered) EditorGadget(1,10,10,480,100,0) ButtonGadget(2,10,120,100,20,"Rückgängig",0) Repeat EventID=WaitWindowEvent() If EventID=#PB_Event_Gadget Select EventGadget() Case 2 SendMessage_(GadgetID(1),#WM_UNDO,0,0) EndSelect EndIf Until EventID = #PB_Event_CloseWindow EndIf