var DropDownMenu = Class.create();

DropDownMenu.prototype = {
 initialize: function(menuElement) {
	menuElement.childElements().each(function(node){
		// if there is a submenu
		var submenu = $A(node.getElementsByTagName("ul")).first();
		if(submenu != null){
			// make sub-menu invisible
			Element.extend(submenu).setStyle({display: 'none'});
			// toggle the visibility of the submenu
			node.onmouseover = node.onmouseout = function(){
				Element.toggle(submenu);
			}
		}
	});
}
};