var dd_timeout = 500;
var dd_timer = null;
var dd_menuitem = 0;

function dd_open()
{	
   dd_canceltimer();
	dd_close();
   dd_menuitem = $(this).find('ul').eq(0).css('visibility', 'visible');
}

function dd_close()
{	
   if (dd_menuitem)
      dd_menuitem.css('visibility', 'hidden');
}

function dd_delayed_close()
{	
   dd_timer = window.setTimeout(dd_close, dd_timeout);
}

function dd_canceltimer()
{	
   if (dd_timer == null)
      return;
   window.clearTimeout(dd_timer);
   dd_timer = null;
}

$(document).ready(function() {	
   $('#drop-down-menu > li').bind('mouseover', dd_open);
   $('#drop-down-menu > li').bind('mouseout', dd_delayed_close);
});

document.onclick = dd_close;