MessageBox确定，取消事件响应

Messagebox.show("Delete?", "Prompt", Messagebox.YES|Messagebox.NO,
     Messagebox.QUESTION,
     new EventListener() {
         public void onEvent(Event evt) {
             switch (((Integer)evt.getData()).intValue()) {
             case Messagebox.YES: doYes(); break; //the Yes button is pressed
             case Messagebox.NO: doNo(); break; //the No button is pressed
             }
         }
     }
 );