【attribute】
<html>
<head>
<script type="text/javascript" src='http://code.jquery.com/jquery-1.5.2.js'></script>
<script type="text/javascript">
$(document).ready(function(){
$("div[id]").one("click", function(){
var idString = $(this).text() + " = " + $(this).attr("id");
$(this).text(idString);
});
});
</script>
</head>
<body>
<div>no id</div>
<div id="hey">with id</div>
</body>
</html>
