window.onload = init;

var interval = 4.5;         // delay between rotating images (in seconds)
var img_count = 30;         // Number of images to rotate through
var current_img;
var t;

function init()
{
    interval *= 1000;               // Convert from s to ms
    
    // Randomly select first image to display
    current_img = Math.floor(Math.random() * img_count);
    
    // Begin rotating images
    t = setTimeout("rotateImage()", interval);
}

function rotateImage()
{
    var img = document.getElementById("banner");
    
    current_img++;
    current_img %= img_count;
    
    img.src = "images/banner/" + current_img.toString() + ".jpg";
    
    t = setTimeout("rotateImage()", interval);
}