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

function jsddm_open(){	
	jsddm_canceltimer();
	jsddm_close();
	ddmenuitem = $(this).find('ul').eq(0).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()
{	$('#menu_topo > li').bind('mouseover', jsddm_open);
	$('#menu_topo > li').bind('mouseout',  jsddm_timer);
});

document.onclick = jsddm_close;