<!DOCTYPE html>
<html>
<head>
<script type='text/javascript'
src='http://code.jquery.com/jquery-1.4.4.min.js'></script>
<style type='text/css'>
.active {
font-size: 20px;
}
</style>
<script type='text/javascript'>
$(window).load(function(){
$("a").click(function(){
$("a.active").removeClass("active");
$(this).addClass("active");
});
});
</script>
</head>
<body>
<a href="#" class="">test 1</a>
<a href="#" class="">test 2</a>
</body>
</html>