// unblock when ajax activity stops 
jQuery.noConflict();
    // Use jQuery via jQuery(...)
    jQuery(document).ready(function(){
        jQuery('.cart_button').click(function() { 
        jQuery.blockUI({ message: '<h1><img src="http://store.versagripps.com/js/jquery/ajax-loader.gif" /><br />Processing your request.<br />Please wait.</h1>' }); 
    }); });