var timeout         = 300;
var closetimer		= 0;
var ddmenuitem      = 0;

function header_navi_open()
{	header_navi_canceltimer();
	header_navi_close();
	ddmenuitem = $(this).find('ul').eq(0).css('visibility', 'visible');}

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

function header_navi_timer()
{	closetimer = window.setTimeout(header_navi_close, timeout);}

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

$(document).ready(function()
{	$('#header_navi > li').bind('mouseover', header_navi_open);
	$('#header_navi > li').bind('mouseout',  header_navi_timer);});

document.onclick = header_navi_close;