public string CreateUser(string uid, string pwd)
        {
            var session    = SessionBuilder.BuildSession(uid, uid, TimeSpan.FromDays(10));
            var execute    = false;
            var encryptPwd = CommonUtilities.Encrypt(pwd);

            DataAccessManager.ExecuteCommand("CreateUser", cmd =>
            {
                dynamic parameters =
                    new { UserID = uid, Password = encryptPwd, Session = session.SessionText };
                execute = cmd.ExecuteNonQuery(parameters) != 0;
            });

            return(execute ? session.SessionText : String.Empty);
        }