window.addEvent('domready', function(){
	// Hide the sections so the CSS doesn't interfere with the JS and then add the events.
	$$('#nav-chapters ul').setStyle('display', 'none');
	$$('#nav-chapters > li').addEvents({
		'mouseenter': function() {
			sub = this.getChildren('ul')[0];
			sub && sub.reveal({'link': 'cancel'});
		},
		'mouseleave': function() {
			sub = this.getChildren('ul')[0];
			sub && sub.dissolve();
		}
	});
});