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

function menu_open() { 
 menu_canceltimer();
 menu_close();
 ddmenuitem = jQuery(this).find('ul').css('visibility', 'visible');
}

function menu_close() {
 if(ddmenuitem) ddmenuitem.css('visibility', 'hidden');
}

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

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

jQuery(document).ready(function()
{  jQuery('#menu > li').bind('mouseover', menu_open)
   jQuery('#menu > li').bind('mouseout',  menu_timer)});

document.onclick = menu_close;