private void ReadUserFile()
{
      if (_MyUsers == null)
      {
        lock (this)
        {
         _MyUsers = new Dictionary<string, MembershipUser>();
         XmlDocument xd = new XmlDocument();
         xd.Load(HostingEnvironment.MapPath(_FileName));
         XmlNodeList xnl = xd.GetElementsByTagName("User");

         foreach (XmlNode node in xnl)
         {
            MembershipUser mu = new MembershipUser(Name,
               node["Username"].InnerText,
               null,
               node["Email"].InnerText,
               String.Empty,
               node["Password"].InnerText,
               true,
               false,
               DateTime.Parse(node["DateCreated"].InnerText),
               DateTime.Now,
               DateTime.Now,
               DateTime.Now,
               DateTime.Now);

               _MyUsers.Add(mu.UserName.ToLower(), mu);
         }
      }
   }
}
