If you need to check which version of jQuery you are running (think Firebug or possibly), you can check the version using the following:
jQuery.fn.jquery
or use the shortcut
$.fn.jquery
Also, if you are loading multiple versions of jQuery on your page and need to verify, you can also use the property:
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.4/jquery.min.js"></script> <script language='JavaScript'> var $_144 = jQuery.noConflict(true); </script> <script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script> <script language='JavaScript'> var $_171 = jQuery.noConflict(true); console.log($_144.fn.jquery); // "1.4.4" console.log($_171.fn.jquery); // "1.7.1" </script>