var inX = 4; // Number of alternative images
var stRandImgURL = new Array(inX);// Array to hold filenames
stRandImgURL[0] = "images/EarthBanner05.jpg";
stRandImgURL[1] = "images/EarthBanner02.jpg";
stRandImgURL[2] = "images/EarthBanner03.jpg";
stRandImgURL[3] = "images/EarthBanner04.jpg";


function pickRandom(range)
{
  if (Math.random)
     return Math.round(Math.random() * (range-1));
  else
  {
    var now = new Date();
    return (now.getTime() / 1000) % range;
  }
}

var url;
var urlParts;
var imageURL;

function setEarthBanner()
{
  url = window.location.href;
  urlParts = url.split("/");

  switch(urlParts[2])
  {
    case "default":
      imageURL = "images/Earthbanner03.jpg";
      textColour = "white";
      break;
    default:
    var choice = pickRandom(inX);
    imageURL = stRandImgURL[choice];
  }
  if (imageURL == "")
  {
    var choice = pickRandom(inX);
    imageURL = stRandImgURL[choice];
  }
}