If OpenWindow(0,0,0,500,250,"Window",#PB_Window_SystemMenu|#PB_Window_ScreenCentered)
  ComboBoxGadget(1,10,10,100,20,#PB_ComboBox_Editable)
  
  SendMessage_(GetWindow_(GadgetID(1),#GW_CHILD),#EM_LIMITTEXT,10,0)
Repeat : Until WaitWindowEvent() = #PB_Event_CloseWindow
EndIf