function menu() {
	var sfEls = document.getElementById("menu").getElementsByTagName("LI");
	for (var i=0; i<sfEls.length; i++) {
		if(sfEls[i].firstChild.nodeName == "SPAN") { 
			sfEls[i].childNodes[2].style.display = "none";
			sfEls[i].firstChild.onclick=function() { 
			    if(this.parentNode.childNodes[2].style.display == "block") {
					this.parentNode.childNodes[2].style.display = "none";
				}
				else {
					this.parentNode.childNodes[2].style.display = "block";
				}	
			}
		}
	}
}
menu();