function BannersManager(urlFlushBanner)
{
  this.urlFlushBanner = urlFlushBanner;
  this.topLeftBannerTimerId = null;
  this.topRightBannerTimerId = null;
  this.bottomBannerTimerId = null;
};

BannersManager.prototype.onImageLoaded = function(bannerType,showingTime)
{
  window.setTimeout("clsBannersManager.loadBanner('" + bannerType + "');",showingTime);
};

BannersManager.prototype.loadBanner = function(bannerType)
{
  var communicator = new AjaxCommunicator();
  if (communicator != null &&
      communicator.isSupportedByBrowser() == true)
  {
    communicator.setUrl(this.urlFlushBanner);
    communicator.setParameter("command","flush_html_code");
    communicator.setParameter("type",bannerType);
    communicator.invoke("",
                        "clsBannersManager.changeBanner",
                        "clsBannersManager.onError");
  }
};

BannersManager.prototype.changeBanner = function(parameters,
                                                 ajaxCommunicator,
                                                 responseText,
                                                 responseXMLObject)
{
  var spanObject = document.getElementById(ajaxCommunicator.getParameter("type") + "_banner");
  if (spanObject != null)
  {
    spanObject.innerHTML = responseText;
  }
};

BannersManager.prototype.onError = function(parameters,
                                            ajaxCommunicator,
                                            responseText,
                                            responseXMLObject)
{
  // alert("Ajax banners error");
};

if (urlFlushBanner)
{
  var clsBannersManager = new BannersManager(urlFlushBanner);
}
else
{
  var clsBannersManager = new BannersManager("./modules/banners/flush_banner.php");
}