一个非常不错的jQuery手风琴式左侧栏导航菜单代码，网站左侧滑动切换收缩展开菜单代码，鼠标悬停链接背景渐显效果。

js代码

$(function() {
	var Accordion = function(el, multiple) {
		this.el = el || {};
		this.multiple = multiple || false;

		// Variables privadas
		var links = this.el.find('.link');
		// Evento
		links.on('click', {el: this.el, multiple: this.multiple}, this.dropdown)
	};

	Accordion.prototype.dropdown = function(e) {
		var $el = e.data.el;
			$this = $(this);
			$next = $this.next();

		$next.slideToggle();
		$this.parent().toggleClass('open');

		if (!e.data.multiple) {
			$el.find('.submenu').not($next).slideUp().parent().removeClass('open');
		}
	};

	var accordion = new Accordion($('#accordion'), false);
	$('.submenu li').click(function () {
		$(this).addClass('current').siblings('li').removeClass('current');
	});
});