jQuery.noConflict();
    
     function centerThis(div) {
        var winH = jQuery(window).height();
        var winW = jQuery(window).width();
        var centerDiv = jQuery('#' + div);
        centerDiv.css('top', winH/2-centerDiv.height()/2);
        centerDiv.css('left', winW/2-centerDiv.width()/2);
    }
    
      // Use jQuery via jQuery(...)
jQuery(document).ready(function(){
       
    jQuery("#submit_button").click(function(){ 
        
        var postcode = jQuery("#postcode").val();
        var product_id = jQuery("#product_id_shipping").val();
        jQuery("#shipping_info").load("/shipping_calculator.php?product_id=" + product_id + "&postcode=" + postcode + "&ajax=1"); 
        centerThis("shipping_results");
        jQuery("#shipping_results").show();
        
        return false;
    });
    
    jQuery("#close").click(function(){
          jQuery("#shipping_results").hide();  
        
    });
    
});