【children_index】
<html>
<head>
<script type="text/javascript" src='http://code.jquery.com/jquery-1.5.2.js'></script>
<script type="text/javascript">
$(document).ready(function(){
$("td:empty").text("Was empty").css('background', 'rgb(255,220,200)');
});
</script>
</head>
<body>
<table>
<tr><td>data</td><td></td></tr>
<tr><td>data</td><td></td></tr>
<tr><td>data</td><td></td></tr>
</table>
</body>
</html>
