怎样屏蔽F5键刷新?

 1<script>   
 2function DisableF5(){   
 3with (event){   
 4// F5 and Ctrl+R   
 5if (keyCode==116 ¦ ¦ (ctrlKey && keyCode==82)){   
 6event.keyCode = 0;   
 7event.cancelBubble = true;   
 8return false;   
 9}   
10}   
11}   
12  
13document.onkeydown = DisableF5;   
14</script>

 1<script language="javascript">   
 2function document.onkeydown()   
 3{   
 4if ((event.keyCode==8) ¦ ¦ //屏蔽退格删除键   
 5(event.keyCode==116) ¦ ¦ //屏蔽 F5 刷新键   
 6(event.ctrlKey && event.keyCode==82)){ //Ctrl + R   
 7event.keyCode=0;   
 8event.returnValue=false;   
 9}   
10}   
11</script>