​x
 
<!DOCTYPE html>
<html>
<head>
<script>
function whichElement(e) {
  var targ;
  if (!e) {
    var e = window.event;
  }
  if (e.target) {
    targ = e.target;
  } else if (e.srcElement) {
    targ = e.srcElement;
  }
  var tname;
  tname = targ.tagName;
  alert("You clicked on a " + tname + " element.");
}
</script>
</head>
<body onmousedown="whichElement(event)">
​
<p>单击文档中的某处。警报框将提醒您单击的元素的名称。</p>
<h3>这是标题</h3>
<img border="0" src="/i/photo/smile.gif" alt="Smiley" width="128" height="128">
<p>这是段落。</p>
​
</body>
</html>
​