var timeout = 500;
var closetimer = 0;
var ddmenuitem = 0;
function menu_open(id)
{
	menu_cancelClosetime();
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
	ddmenuitem = document.getElementById(id);
	ddmenuitem.style.visibility = 'visible';

}
function menu_close()
{
	if(ddmenuitem) ddmenuitem.style.visibility = 'hidden';
}
function menu_closetime()
{
	closetimer = window.setTimeout(menu_close, timeout);
}
function menu_cancelClosetime()
{
	if(closetimer)
	{
		window.clearTimeout(closetimer);
		closetimer = null;
	}
}
document.onclick = menu_close;