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

function jsddm_open(){

	jsddm_canceltimer();
	jsddm_close();
	ddmenuitem = $(this).find('ul').eq(0).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(){
	$('#header_menu >ul> li').hover(jsddm_open,jsddm_timer);

});

document.onclick = jsddm_close;