Global lpPrevFunc

Procedure ChildSubProc(hWnd,uMsg,wParam,lParam)
  Select uMsg
    Case #WM_LBUTTONDBLCLK
      MessageRequester("","Es wurde auf Tab "+Str(GetGadgetState(1))+" doppel geklickt.",0)
  EndSelect
  
  ProcedureReturn CallWindowProc_(lpPrevFunc,hWnd,uMsg,wParam,lParam)
EndProcedure

If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
  PanelGadget(1,10,10,480,230)
    AddGadgetItem(1,-1,"Paneltab 1",0,0)
    AddGadgetItem(1,-1,"Paneltab 2",0,0)
    AddGadgetItem(1,-1,"Paneltab 3",0,0)
  CloseGadgetList()
  
  lpPrevFunc = SetWindowLongPtr_(GadgetID(1),#GWL_WNDPROC,@ChildSubProc())
  
Repeat : Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf