/// <summary>
 /// Attempt to login the user by matching their AD account to a registered user in the system
 /// </summary>
 /// <param name="userName"></param>
 /// <returns></returns>
 public int? Login(string userName)
 {
     try
     {
         int? rtrn;
         using (var serviceClient = new NeonISGDataServiceClient(Configuration.ActiveNeonDataServiceEndpoint))
         {
             rtrn = serviceClient.Login(userName);
         }
         return rtrn;
     }
     catch (Exception ex)
     {
         throw new Exception(string.Format("Error in SecurityVM.Login() userName:{0}", userName), ex);
     }
 }