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

function jsddm_open()
{  jsddm_canceltimer();
   jsddm_close();
   ddmenuitem = $(this).find('ul').css('visibility', 'visible');
}

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

function jsddm_timer()
{  closetimer = window.setTimeout(jsddm_close, timeout);
}

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

$(document).ready(function()
{  
   $('#navigation > li').bind('mouseover', jsddm_open)
   $('#navigation > li').bind('mouseout',  jsddm_timer)

});

document.onclick = jsddm_close;