Hey ya'll I have this code here and it suppose to add the class name "cboxElement"

$(".wpcart_gallery a:first").addClass("cboxElement");

but it does not work.

I have the proper Jquery file in my header, I have surrounded this in jQuery('document').ready(function($){......}); and it works for all my other Jquery but the add class call.

here is what I am trying to add the class to...

<div class="wpcart_gallery" style="text-align:center; padding-top:5px;">
<a class="thickbox" href="DSC_0037.jpg" rev="DSC_0037.jpg"></a>
</div>

Anybody know why this isnt working? I am new to jquery

this is also in wordpress hence the jQuery('document')