If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
  ButtonGadget(1,10,10,100,20,"Entfernen",0)
  
  If CreateMenu(0,WindowID(0))
   MenuTitle("Programm")
     MenuItem(1,"Beenden")
  EndIf
Repeat
EventID=WaitWindowEvent()
If EventID=#PB_Event_Gadget
  Select EventGadget()
   Case 1
     RemoveMenu_(MenuID(0),1,0)
  EndSelect
EndIf
Until EventID = #PB_Event_CloseWindow
EndIf