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

function dropdown_open() {  
	dropdown_canceltimer();
	dropdown_close();
	ddmenuitem = $(this).find('ul').css('visibility', 'visible');
}

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

function dropdown_timer() {
	closetimer = window.setTimeout(dropdown_close, timeout);
}

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

$(document).ready(function() {
	$('#start_navigation_list > li').bind('mouseover', dropdown_open)
	$('#start_navigation_list > li').bind('mouseout',  dropdown_timer)
});
document.onclick = dropdown_close;