JavaScript DHTML/jQuery/load
Load event
<html>
<head>
<script type="text/javascript" src="js/jquery-1.3.2.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$("input").load(function(){
if($(this).height() > 100) {
$(this).addClass("big");
}
});
});
</script>
</head>
<body>
<body>
<input type="text" />
</body>
</html>