var timeout    = 500;
 var closetimer = 0;
 var ddmenuitem = 0;

 function menu_open(){  
   menu_canceltimer();
   menu_close();
   ddmenuitem = $(this).find('ul').css('display', 'block');
 }

 function menu_close(){  
   if(ddmenuitem) ddmenuitem.css('display', 'none');
 }

 function menu_timer(){  
   closetimer = window.setTimeout(menu_close, timeout);
 }

 function menu_canceltimer(){  
   if(closetimer){  
     window.clearTimeout(closetimer);
     closetimer = null;
   }
 }
 
 document.onclick = menu_close;