var timeout    = 100;
var closetimer = 0;
var ddmenuitem;
function ddOpen()
{
  cancelTimer();
  ddClose();
  ddmenuitem = $(this).find('ul').css('visibility', 'visible');
}

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

function ddTimer()
{  
    closetimer = window.setTimeout(ddClose, timeout);
}

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

$(document).ready(function(){
  $('#dropdownMenu > li').bind('mouseover', ddOpen);
  $('#dropdownMenu > li').bind('mouseout',  ddTimer);
});

document.onclick = ddClose;