public void UpdateTimeslots()
 {
     AvaliableTimes = StaffDBConverter.GetAvaliableTimeslots(SelectedDate, RequestedDoctor, RequestedGender);
     if (AvaliableTimes.Rows.Count <= 0)
     {
         NoAvaliableTime = "No Avaliable Times.";
     }
     else
     {
         NoAvaliableTime = "";
     }
 }
        public ReservationAppointmentViewModel()
        {
            _dialogService = new DialogBoxService();
            if (IsInDesignMode)
            {
                SelectedDate = DateTime.Parse("17/02/2000");
            }
            else
            {
                if (DateTime.Today.Date.DayOfWeek == DayOfWeek.Friday)
                {
                    SelectedDate = DateTime.Now.AddDays(3).Date;
                }
                else if (DateTime.Today.Date.DayOfWeek == DayOfWeek.Saturday)
                {
                    SelectedDate = DateTime.Now.AddDays(2).Date;
                }
                else
                {
                    SelectedDate = DateTime.Now.AddDays(1).Date;
                }
            }
            AvaliableTimes = StaffDBConverter.GetAvaliableTimeslots(SelectedDate, RequestedDoctor, RequestedGender);
            if (AvaliableTimes.Rows.Count <= 0)
            {
                NoAvaliableTime = "No Avaliable Times.";
            }
            else
            {
                NoAvaliableTime = "";
            }

            MessengerInstance.Register <DateTime> (
                this,
                (action) => UpdateTimeslots()
                );
            MessengerInstance.Register <int>(this, UpdateTimeslotIndex);
            // When patientID message is received (from PatientDBConverter), set patient ID in VM.
            MessengerInstance.Register <double>(this, SetPatientID);
            BookAppointmentCommand = new RelayCommand(BookAppointment);
        }