var timeout    = 1000;
var closetimer = 500;
var ddmenuitem = 0;

function navi_open()
{  navi_canceltimer();
   navi_close();
   ddmenuitem = $(this).find('ul').css('visibility', 'visible');}

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

function navi_timer()
{  closetimer = window.setTimeout(navi_close, timeout);}

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

$(document).ready(function()
{  $('#navi > li').bind('mouseover', navi_open)
   $('#navi > li').bind('mouseout',  navi_timer)});

document.onclick = navi_close;