// initialise plugins
    jQuery(function(){
        jQuery('ul#top_nav').superfish({
        delay:       500,                             // .5 second delay on mouseout 
        animation:   {opacity:'show',height:'show'},  // fade-in and slide-down animation 
        speed:       'fast',                          // faster animation speed 
        autoArrows:  false,                           // disable generation of arrow mark-up 
        dropShadows: false                            // disable drop shadows 
        });
    });