private void btnCancelExm_Click(object sender, RoutedEventArgs e)
        {
            ExaminationDTO examinationToCancel = (ExaminationDTO)dgExaminations.SelectedItem;

            if (examinationToCancel == null)
            {
                var okMb = new OKMessageBox(this, 0);
                okMb.titleMsgBox.Text = "Greška";
                okMb.textMsgBox.Text  = "Odaberite pregled koji želite otkazati!";
                okMb.ShowDialog();
            }
            else if (examinationToCancel.Room.Equals(""))
            {
                var okMb = new OKMessageBox(this, 0);
                okMb.titleMsgBox.Text = "Greška";
                okMb.textMsgBox.Text  = "Izabrani termin nije zakazan!";
                okMb.ShowDialog();
            }
            else
            {
                string[] partsDoctor = examinationToCancel.Doctor.Split(' ');
                if (examinationController.CancelExamination(examinationToCancel.Id) == false)
                {
                    var okMb = new OKMessageBox(this, 0);
                    okMb.titleMsgBox.Text = "Greška";
                    okMb.textMsgBox.Text  = "Došlo je do greške prilikom otkazivanja pregleda!";
                    okMb.ShowDialog();
                    return;
                }
                int    lastId  = notificationController.getLastId();
                string message = "Vas pregled za datum " + examinationToCancel.Date + " u " + examinationToCancel.Time + " sati je otkazan.";

                string[] partsPatient = examinationToCancel.Patient.Split(' ');
                notificationController.SendNotification(new Notification(++lastId, TypeOfNotification.Pregled, message, partsPatient[partsPatient.Length - 1]));

                foreach (Window window in Application.Current.Windows)
                {
                    if (window.GetType() == typeof(MainWindow))
                    {
                        (window as MainWindow).Main.Content = new ExaminationViewByDoctor(partsDoctor[partsDoctor.Length - 1]);
                    }
                }
            }
        }