禁止用F5键和禁止右键弹出菜单

//禁止用F5键   function   document.onkeydown()   {             if   (   event.keyCode==116)             {                     event.keyCode   =   0;                     event.cancelBubble   =   true;                     return   false;             }   }       //禁止右键弹出菜单   function   document.oncontextmenu()   {         return   false;   }   

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