var slides = new Array(
            new slide("", "mainslide1"),
            new slide("", "mainslide2"),
            new slide("", "mainslide3"),
            new slide("", "mainslide4"));

var fadeOutTime = 400;
var fadeInTime = 500;
var stepNextTime = 10000;

function slide(contentHtml, contentClass) {
    this.contentHtml = contentHtml;
    this.contentClass = contentClass;
}

var currentTimeOut;
var currentstep = 0;

var backgrounddiv;
var contentdiv;

function step() {
    currentstep++;
    if (currentstep >= slides.length)
        currentstep = 0;
    gotoSlide(currentstep);
}

function gotoSlide(step) {
    currentstep = step;
    clearTimeout(currentTimeOut);
    $("#slides_background").fadeOut(fadeOutTime, function () {
        backgrounddiv.className = slides[currentstep].contentClass;
        $("#slides_background").fadeIn(fadeInTime);
    });

    currentTimeOut = setTimeout('step()', stepNextTime);
}

$(document).ready(function () {
    backgrounddiv = document.getElementById('slides_background');
    gotoSlide(0);
});