html 屏蔽键盘事件,鼠标右键

window.onload = function(){
    //屏蔽键盘事件
     document.onkeydown = function (){
         var e = window.event || arguments[0];
         //F12
         if(e.keyCode == 123){
             return false;
         //Ctrl+Shift+I
         }else if((e.ctrlKey) && (e.shiftKey) && (e.keyCode == 73)){
             return false;
         //Shift+F10
         }else if((e.shiftKey) && (e.keyCode == 121)){
             return false;
         //Ctrl+U
         }else if((e.ctrlKey) && (e.keyCode == 85)){
             return false;
         }
     };
     //屏蔽鼠标右键
     document.oncontextmenu = function (){
         return false;
     }
}