<html>
<head>
<script type="text/javascript" src='http://code.jquery.com/jquery-1.5.2.js'></script>
<script type="text/javascript">
$(document).ready(function(){
$("p").hide();
});
</script>
</head>
<body>
<p class="myClass">p</p>
<span class="myClass">span class="myClass"</span>
</body>
</html>