(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", this)[0] || $($li[0]).addClass("current")[0];
            $li.not(".back").hover(function () { move(this) }, noop);
            $(this).hover(noop, function () { move(curr) });
            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);