Infinited Slide Scroller (jQuery)

For StackOveflow Question: http://stackoverflow.com/questions/9945145/how-do-i-make-this-slider-javascript-to-simply-rotate-images-infinitely/9946187#9946187

HTML

<ul id="slides">
    <li>Slide1</li>
    <li>Slide2</li>
    <li>Slide3</li>
    <li>Slide4</li>
    <li>Slide5</li>
    <li>Slide6</li>
</ul>

CSS

ul#slides {position:relative; width:400px; height:200px; overflow:hidden;}
ul#slides > li {
    position:absolute;
    top:0px;
    left:100%;
    width:100%;
    height:100%;
    background:#000;
    color:#FFF;
    z-index:1;
}

ul#slides > li:nth-child(even) {background:#fff;}

JavaScript

if ($('#slides').length != 0) {
    var currentIndex = 0, slides = $('#slides > li');
    $(slides[currentIndex]).css('left','0%');
    function slide() {
        var current, next;
        current = $(slides[currentIndex]);
        currentIndex++;
        if(currentIndex === slides.length){
            currentIndex = 0;   
        }
        next = $(slides[currentIndex]);
        next.css('left','100%');
        next.css('z-index',parseInt(current.css('z-index'), 10)+1);
        next.animate({left: '0%'}, 1000);
    }        
    var s = window.setInterval(slide, 3000);        
}