function openmenu(id) {
  if (document.getElementsByClassName) {
		var submenus = document.getElementsByClassName('submenu');
		for (var i = 0; i < submenus.length; i++) {
			submenus[i].style.display = 'none';
		}
  } else {
		i = 0;
		a = document.getElementsByTagName("ul");
		while (element = a[i++]) {
			if (element.className == "submenu") {
				a[i-1].style.display = 'none';
			}
		}
	}
	document.getElementById(id).style.display = 'block';
}