function CDNFailed(evt) {
  function setCookie(c_name,value,expiredays) {
    var exdate=new Date();
    exdate.setHours(exdate.getHours() + (expiredays *24));
    document.cookie=c_name+ "=" +escape(value)+
    ((expiredays==null) ? "" : ";path=/;expires="+exdate.toGMTString());
  }
  function getCookie(c_name) {
    if (document.cookie.length>0) {
      c_start=document.cookie.indexOf(c_name + "=");
      if (c_start!=-1) {
        c_start=c_start + c_name.length+1;
        c_end=document.cookie.indexOf(";",c_start);
        if (c_end==-1) c_end=document.cookie.length;
        return unescape(document.cookie.substring(c_start,c_end));
      }
    }
    return "";
  }

  if (getCookie('CDNFailed')) {
    // CDN is already disabled
    return;
  }
  setCookie('CDNFailed', 1, 0.5);
  var oRequest = new Ajax.Request(CDN_ERROR_URL, {
    method:'post',
    parameters:'url=' + escape(window.location.href),
    onComplete: function() {
          if (CDN_RELOAD_ON_ERROR) {
            window.location.reload()
          }
        }
      }
    );
}