public string CancelUserAppointment(int id, int doctorId, int userId, string mobileNo)
        {
            int rowAffected = aDoctorGateway.CancelUserAppointment(id, doctorId, userId, mobileNo);

            if (rowAffected > 0)
            {
                return("Success");
            }
            else
            {
                return("Appointment canceling failed. Try again!");
            }
        }