$(function () {
    var slideIndex = 1;
    var numSlides = $("ul.board li").size();
    
    setInterval(function () {
        slideIndex++;

        if (slideIndex > numSlides)
            slideIndex = 1;

        $("ul.board li").fadeOut();
        $("ul.board li:nth-child(" + slideIndex + ")").fadeIn();
    }, 5000);
});