private void BtnEditer_Click(object sender, RoutedEventArgs e)
 {
     if (listViewReservations.SelectedIndex >= 0)
     {
         EditReservationWindow erw = new EditReservationWindow((listViewReservations.SelectedItem as Reservation).Id);
         erw.ShowDialog();
         listViewReservations.ItemsSource = DAL.GetReservations();
     }
 }
        private void ListViewReservations_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            if (listViewReservations.SelectedIndex < 0)
            {
                return;
            }

            EditReservationWindow erw = new EditReservationWindow((listViewReservations.SelectedItem as Reservation).Id);

            erw.ShowDialog();
            listViewReservations.ItemsSource = DAL.GetReservations();
        }