Event.observe(document, 'dom:loaded', function () {
	$$('#topnav .o').invoke('removeClassName','o');

	var currentmenu;
	$('topnav').observe('mouseover', function (event) {
		var element = event.element();
		var menuname;

		if (element.tagName=='A' && (menuname = element.getAttribute('menu'))) {
			$$('#topnav .o').invoke('removeClassName','o');

			var l = element.offsetLeft;
			element.addClassName('o');
			
			if (currentmenu) currentmenu.hide();
			currentmenu = $(menuname).show().setStyle({left:l+'px'});
			event.stop();return;
		}
		
		if (currentmenu) {
			$$('#topnav .o').invoke('removeClassName','o');
			currentmenu.hide();
		}
		event.stop();
	});
	
	var mout = function () {
		this.hide();
		$$('#topnav .o').invoke('removeClassName','o');
		if (currentmenu==this) currentmenu = null;
	};
	
	$$('#subnav>div').each(function (e) {e.observe('mouseleave',mout);});

});