var header_images = new Array();
header_images[0] = "header-background-1.jpg";
header_images[1] = "header-background-2.jpg";
header_images[2] = "header-background-3.jpg";
var header_image_index = 0;
var header_image_timer = null;

function header_toggleImage() {
    header_image_index = Math.floor(Math.random() * (header_images.length-1));
    header_loadImage();
}

function header_loadImage() {
    var img = new Image();
    $(img).load(function () {
        $("#banner_zone").attr('style','background: url("/images/' + header_images[header_image_index] + '") left top no-repeat');
    }).attr('src','/images/' + header_images[header_image_index]);
    
    header_image_timer = window.setTimeout('header_getNextImage();', 7000);
}

function header_getNextImage() {
    if (header_image_timer)
        window.clearTimeout(header_image_timer);

    header_image_timer = null;
    if (header_image_index == (header_images.length-1))
        header_image_index = 0;
    else
        header_image_index++;
    header_loadImage(); //load the next header image.
}

$(document).ready(function () {
    header_toggleImage();
});