private void Save_Click(object sender, RoutedEventArgs e)
        {
            bool daneOK = true;

            int count         = MiejscaDoZarezerwowania.Count();
            int countDistinct = MiejscaDoZarezerwowania.Distinct().Count();

            if (count == countDistinct)
            {
                try
                {
                    using (ClientServiceClient cs = new ClientServiceClient())
                    {
                        List <ReservationPositionModel> res = cs.GetActualCinemaHallState(DaneSeansu.SalaID).ToList();

                        foreach (PositionData pos in MiejscaDoZarezerwowania)
                        {
                            if (res.Where(x => x.Position == pos.Position && x.Row == pos.Row).FirstOrDefault() == null)
                            {
                                cs.AddReservationSinglePosition(DaneSeansu.SalaID, parent.loggedUser.ClientID, pos.Row, pos.Position);
                            }
                        }
                    }
                    this.Close();
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.ToString());
                }
            }
        }