private XDocument GetXDocument(string url)
{
  Uri uri = new Uri(url);
  System.Net.WebClient wb = new System.Net.WebClient();
  wb.Proxy.Credentials = System.Net.CredentialCache.DefaultCredentials;
  MemoryStream ms = new MemoryStream(wb.DownloadData(uri));
  System.Xml.XmlTextReader rdr = new System.Xml.XmlTextReader(ms);
  XDocument doc = XDocument.Load(rdr);
  return doc;
}