/* ROTATING BANNER --------------------------------------------------------- */

var bannerTimer = new Array();
var currentBanners = new Array();
var durations = new Array();

function rotateBanner(zoneId) {

  bannerObjects = document.getElementsByName('rotatingBanner['+zoneId+']');

  if (bannerObjects.length == 0)
    return;

  if (typeof(currentBanners[zoneId]) == 'undefined')
    currentBanner = -1;
  else
    currentBanner = currentBanners[zoneId];

  /*
   * Initialize
   */
  if (currentBanner == -1) {
    for (i=0; i < bannerObjects.length; i++)
      bannerObjects[i].style.display = 'none';
    currentBanner = 0;
  }

  /*
   * Hide old banner
   */
  bannerObjects[ currentBanner ].style.display = 'none';
  
  /*
   * Advance / wrap
   */
  currentBanner++;
  if (currentBanner >= bannerObjects.length)
    currentBanner = 0;
  
  /*
   * Show new banner
   */
  bannerObjects[ currentBanner ].style.display = 'block';

  currentBanners[zoneId] = currentBanner;
  bannerTimer[zoneId] = setTimeout('rotateBanner('+zoneId+')', durations[zoneId][ currentBanner ]);
}