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

function jsddm_open() {  
	jsddm_canceltimer();
	jsddm_close();
	ddmenuitem = $(this).find('ul').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() {  
	$('#main_menu > li').bind('mouseover', jsddm_open)
	$('#main_menu > li').bind('mouseout',  jsddm_timer)
	$('#main_menu > li').bind('onclick', jsddm_open)
});

document.onclick = jsddm_close;