var interval = 3; // delay between rotating images (in seconds)
var random_display = 1; // 0 = sequential, 1 = random
interval *= 1000;

//var image_index = 0;
image_list = new Array();

var count = 21;

for(var i = 1; i<count; i++)
{
    image_list[i] = new imageItem("/images/rotator/"+i+".jpg");
}

var number_of_image = image_list.length;

function imageItem(image_location)
{
    this.image_item = new Image();
    this.image_item.src = image_location;
    }
    function get_ImageItemLocation(imageObj) {
    return(imageObj.image_item.src)
}

function generate(x, y)
{
    var range = y - x + 1;
    return Math.floor(Math.random() * range) + x;
}

function getNextImage()
{
    if (random_display) {
    image_index = generate(0, number_of_image-1);
    }
    else {
    image_index = (image_index+1) % number_of_image;
    }
    var new_image = get_ImageItemLocation(image_list[image_index]);
    return(new_image);
}

function rotateImage(place)
{
    var new_image = getNextImage();
    document[place].src = new_image;
    var recur_call = "rotateImage('"+place+"')";
    setTimeout(recur_call, interval);
}