var timeout    = 500;
var closetimer = 0;
var ddimagesitem = 0;

function images_open()
{  images_canceltimer();
   images_close();
   ddimagesitem = $(this).find('ul').css('visibility', 'visible');}

function images_close()
{  if(ddimagesitem) ddimagesitem.css('visibility', 'hidden');}

function images_timer()
{  closetimer = window.setTimeout(images_close, timeout);}

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

$(document).ready(function()
{  
   $('#images > li').bind('mouseover', images_open)
   $('#images > li').bind('mouseout',  images_timer)});

document.onclick = images_close;