If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered|#PB_Window_Invisible)
  SetWindowLongPtr_(WindowID(0), #GWL_EXSTYLE, GetWindowLongPtr_(WindowID(0), #GWL_EXSTYLE) | #WS_EX_DLGMODALFRAME)
  HideWindow(0, 0)
Repeat : Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf