$(document).ready(function(){  
     
       /* $("#menu li ul.subnav").parent().append("<span></span>"); */
      $('li.submenu').hover(  
         function () {  
             //show its submenu  
             $('ul', this).slideDown("medium");  
   
         },   
         function () {  
             //hide its submenu  
             $('ul', this).slideUp("fast");           
         }  
     );  
								});