private void Refresh()
        {
            Visits.ItemsSource           = ClassSqlAppointment.AppointmentsForDataGrid(((ClassTerm)DateVisitComboBox.SelectedItem).Date);
            HistoryofPacient.ItemsSource = ClassSqlAppointment.GetAllApoitmentsForPatien(lastSelectedAppointmentHistoryVistis);

            Visits.SelectedIndex           = lastSelectedIndexVisits;
            HistoryofPacient.SelectedIndex = lastSelectedIndexHistoryVistis;
        }
        private void Vistis_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            if (Visits.SelectedItem != null)
            {
                lastSelectedAppointmentVisits = (ClassAppointment)Visits.SelectedItem;
                lastSelectedIndexVisits       = Visits.SelectedIndex;

                HistoryofPacient.ItemsSource = null;
                HistoryofPacient.ItemsSource = ClassSqlAppointment.GetAllApoitmentsForPatien((ClassAppointment)Visits.SelectedItem);
            }
        }