//Close all open slides in #nav_main that's not currently active.
var closeAll = function() {
	$$('#nav_main li ul').each(function(el) {
		var parent = el.getParent('li');
		if (!parent.hasClass('active')) {
			parent.retrieve('slide').slideOut();
		}
	})
}

window.addEvent('domready', function() {

	$$('ul#nav_main li ul').each(function(el) {
		var parent = el.getParent('li');
		parent.addClass('dropdown');
		parent.store('slide', new Fx.Slide(el).hide());
		parent.getElement('a').addEvent('click', function(e) {
			e.stop();
			$$('#nav_main li').removeClass('active');
			parent.addClass('active');
			closeAll();
			parent.retrieve('slide').toggle();
			
		});
	});
	
	//Show the ul of which parent li has class .active
	$$('#nav_main li ul').each(function(el){
		var parent = el.getParent('li');
		if (parent.hasClass('active')) {
			parent.retrieve('slide').show();
		}
	})

})