<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html><head>
<meta content="text/html; charset=windows-1251" http-equiv="Content-Type">
<script type="text/javascript">
document.addEventListener('click', function(event) {
var target = event ? event.target : window.event.srcElement;
alert(target.tagName);
}, false);
</script>
</head><body>
<div>div</div>
<span>span</span><br>
<font>font</font>
</body></html>
Всё работает