function excol(index){
	var subMenus = document.getElementById("mainmenu").getElementsByTagName("ul");
	for (var i=0; i<subMenus.length; i++) {
			if (i==index){
				subMenus[i].style.display = "block";
			}
			else {
				subMenus[i].style.display = "none";
			}
	}
}