title: Coco2d add UIalert or UITextField,first time can show normal ,but next show will badly show two times
body: <p>Coco2d add UIalert,first time can show normal ,but next show will badly show two times,and when i add  UITextField to cocos2d for input  player information,when I leave this scene ,I 'm<br>
  sure UITextField have been release ,but in other scene this UITextField still on the screen</p>