$(function() {

    var slideBox = $('#sliderBox');
    var totalItems = slideBox.children().size();
    var w = totalItems * 600;
    slideBox.css('width', w + 'px');


    function slideIt() {
        slideBox.animate({
            opacity:.6
        })
                .animate({
                    marginLeft: (slideBox.css('margin-left').split('px')[0] <= ((w - (w * 2) + 600)) ? 0 : '-=600')
                }, 'fast', 'easeInOutQuint')
                .animate({
                    opacity:1
                });
        window.setTimeout(slideIt, 3000);
    }

    slideIt();
});