Looks for the class 'selected' on the matched elements.
<html> <head> <script type="text/javascript" src="js/jquery-1.3.2.js"></script> <script type="text/javascript"> $(document).ready(function(){ $("p:last").addClass("selected highlight"); alert($("p:last").hasClass("selected").toString()); }); </script> <style> .selected { color:red; } .highlight { background:yellow; } </style> </head> <body> <body> <p>A</p> <p>B</p> <p>C</p> </body> </html>