EnableExplicit

Define EventID

If OpenWindow(0,0,0,500,400,"Window",#PB_Window_BorderLess)
  ButtonGadget(1,10,10,100,20,"Button",0)
  
  SetCursorPos_(15,15)
  mouse_event_(#MOUSEEVENTF_LEFTDOWN,0,0,0,0)
  mouse_event_(#MOUSEEVENTF_LEFTUP,0,0,0,0)
  
  Repeat
    EventID=WaitWindowEvent()
    If EventID=#PB_Event_Gadget
      Select EventGadget()
        Case 1
          MessageRequester("","Auf den Button wurde geklickt.",0)
          End
      EndSelect
    EndIf
    If EventID = #PB_Event_CloseWindow
      End
    EndIf
  ForEver
EndIf