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

function menu_dropdown_open() {
	if (ddmenuitem) {
		ddmenuitem.slideUp(0);
		if( ddmenuitem.is(':animated') ) return;
	}
	menu_dropdown_canceltimer();
	menu_dropdown_close(true);
//	ddmenuitem = $(this).find('ul').css('visibility', 'visible');
	ddmenuitem = $(this).find('ul').slideDown(250);
}

function menu_dropdown_close(instant) {
	var close = 250;
	if (instant) close = 0;
	if (ddmenuitem) ddmenuitem.slideUp(close);
}

function menu_dropdown_timer() {
	closetimer = window.setTimeout(menu_dropdown_close, timeout);
}

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

$(document).ready(function() {
	$('.menu_dropdown > li').hover(menu_dropdown_open,menu_dropdown_timer);
	$('.tab_menu_dropdown > li').hover(menu_dropdown_open,menu_dropdown_timer);
	/*bind('mouseover', menu_dropdown_open)
	$('.menu_dropdown > li').bind('mouseout',  menu_dropdown_timer)*/
	$(document).click(menu_dropdown_close);
});