var interval = 3; // delay between rotating images (in seconds)
var random_display = 0; // 0 = no, 1 = yes
var image_index = 0;
var image_list = new Array();
var number_of_image = 0;
var image_directory = "images/";

interval *= 1000;

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;
  }

  return(image_list[image_index]);
}

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

function rotateInit(place, image_names) {
  if (!document.getElementById(place) || document.getElementById(place) == null )
    return;

  for ( var i = 0; i < image_names.length; i++ )
  {
    image_list[i] = new String( image_directory + image_names[i] );
  }

  number_of_image = image_list.length;
  image_index = -1;
  
  rotateImage(place);
}


function rotateInitD(place, image_names, delay) {
  interval = delay * 1000;
  rotateInit(place, image_names);
}

function rotateInitR(place, image_names) {
  random_display = 1;
  rotateInit(place,image_names);
}