If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
  ButtonGadget(1,10,10,100,20,"Button ohne Skin",0)
  ButtonGadget(2,10,40,100,20,"Button mit Skin",0)
  
  SetWindowTheme_(GadgetID(1),@Null,@Null)
Repeat : Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf