function sottomenu(num_button) {
	nome_layer = "Layer_" + num_button;
	a = document.getElementById(nome_layer);
	if (a.style.visibility == "hidden") {
		a.style.visibility="visible";
	} else {
		a.style.visibility="hidden";
	}
	
}

//navHover = function() {
//	var lis = document.getElementById("navmenu2").getElementsByTagName("LI");
//	for (var i=0; i<lis.length; i++) {
//		lis[i].onmouseover=function() {
//			this.className+=" iehover";
//		}
//		lis[i].onmouseout=function() {
//			this.className=this.className.replace(new RegExp(" iehover\\b"), "");
//		}
//	}
//}
//if (window.attachEvent) window.attachEvent("onload", navHover);