17.2.2 ctrkey、ctrleft属性.html

javascript即用即差核心对象手册

<form>
   <input type="button" value="点击该按钮" onclick="onevent(this)" />
   <div id="info"></div>
</form>
<script>
    function onevent(btn)
	{
	   if(event.ctrlKey)
	       {
		        btn.value="单击的同时按下了Ctrl键";
				document.all.info.innerHTML+=btn.value+"<br>";
		     	if(event.ctrlLeft)
	              {
		              btn.value="单击的同时按下了左Ctrl键";
					  document.all.info.innerHTML+=btn.value+"<br>";
			          return;
			       } 
				 return;
			}
	   btn.value="单击时没有按下Ctrl键";
	   document.all.info.innerHTML+=btn.value+"<br>";
	}
</script>