<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<div id="d">
</div>
<script type="text/javascript" src="http://code.jquery.com/jquery-1.10.2.min.js"></script>
<style type="text/css">
#d
{
width: 30px;
height: 300px;
}
</style>
<script type="text/javascript">
alert($('#d').height());
</script>
</body>
</html>