Event.onDOMReady(function() {
	var viewer = new AC.ViewMaster.Viewer($$('.swap-content'), $('design-view'), 'design-trigger', {
		shouldAnimateContentChange: false,
		initialId: 'expansion'
	});

	function updateSubnav(incoming) {
		var li = incoming.triggers().first().up('li');
		li.addClassName('active');
		li.up('ul').className = li.id;
	}

	viewer.setDelegate({
		willShow: function(view, outgoing, incoming) {
			updateSubnav(incoming);
			if (outgoing) outgoing.triggers().first().up('li').removeClassName('active');
		},
		didShow: function(view, outgoing, incoming) {
			// willShow doesn't get called on the initial view
			if (!outgoing) updateSubnav(incoming);
		}
	});
	
	var tracker = new AC.ViewMaster.Tracker();
});