<html>  
<!--//this code by hongseheike-->  
<head>  
<script language="javascript">  
  ns4 = (document.layers) ? true : false;    
  ie4 = (document.all) ? true : false;    
function keyDown(e){    
  if(ns4){    
  var nkey=e.which;    
  var iekey='现在是ns浏览器';    
  var realkey=String.fromCharCode(e.which);    
}    
  if(ie4){    
  var iekey=event.keyCode;    
  var nkey='现在是ie浏览器';    
  var realkey=String.fromCharCode(event.keyCode);    
  if(event.keyCode==32){realkey='\' 空格\''}    
  if(event.keyCode==13){realkey='\' 回车\''}    
  if(event.keyCode==27){realkey='\' Esc\''}    
  if(event.keyCode==16){realkey='\' Shift\''}    
  if(event.keyCode==17){realkey='\' Ctrl\''}    
  if(event.keyCode==18){realkey='\' Alt\''}    
}    
  alert('ns浏览器中键值:'+nkey+'\n'+'ie浏览器中键值:'+iekey+'\n'+'实际键为'+realkey);    
}    
document.onkeydown = keyDown;    
if(ns4){    
document.captureEvents(Event.KEYDOWN);}    
</script>  
</head>  
<body>  
//Javascript Document    
<hr>  
<center>  
<h3>请按任意一个键。。。。</h3>  
</center>  
</body>  
</html>