(function ($) { $.fn.lavaLamp = function (o) { o = $.extend({ fx: "linear", speed: 500, click: function () { } }, o || {}); return this.each(function () { var b = $(this), noop = function () { }, $back = $('<li class="back"><div class="left"></div></li>').appendTo(b), $li = $("li", this), curr = $("li.current_page_item", this)[0] || $($li[0]).addClass("current_page_item")[0]; $li.not(".back").hover(function () { move(this) }, noop); $(this).hover(noop, function () { move(curr) }); $li.click(function (e) { setCurr(this); return o.click.apply(this, [e, this]) }); setCurr(curr); function setCurr(a) { $back.css({ "left": a.offsetLeft + "px", "width": a.offsetWidth + "px" }); curr = a }; function move(a) { $back.each(function () { $(this).dequeue() }).animate({ width: a.offsetWidth, left: a.offsetLeft }, o.speed, o.fx) } }) } })(jQuery);