var timeout    = 500;
var closetimer = 0;
var mainNavItem = 0;

function mainNav_open(){
	mainNav_canceltimer();
	mainNav_close();
	mainNavItem = $(this).find('ul').css('visibility', 'visible');
	}

function mainNav_close(){
	if(mainNavItem) mainNavItem.css('visibility', 'hidden');
	}

function mainNav_timer(){
	closetimer = window.setTimeout(mainNav_close, timeout);
	}

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

	function mainNav_hoverIn() {
		var img = $(this).find('img:first');
		var srcVal = $(img).attr('src');
		$(img).attr('src', srcVal.replace('.', '_over.'));
	}

	function mainNav_hoverOut() {
		var img = $(this).find('img:first');
		var srcVal = $(img).attr('src');
		$(img).attr('src', srcVal.replace('_over.', '.'));
	}
	
$(document).ready(function() {
	$('#mainNav > li').bind('mouseover', mainNav_open)
	$('#mainNav > li').bind('mouseout', mainNav_timer)
	$('#mainNav > li').bind('mouseover', mainNav_hoverIn)
	$('#mainNav > li').bind('mouseout', mainNav_hoverOut)
});
document.onclick = mainNav_close;