public FlightBook(Flight f)
        {
            InitializeComponent();

            this.selectedFlight = f;

            tb_vid.Text = f.flightID + "";

            using (FlightServiceClient fsc = new FlightServiceClient())
            {
                foreach (string s in fsc.getAirPlaneClasses())
                    cb_klasse.Items.Add(s);

                cb_klasse.SelectedIndex = 0;
            }
        }
        public FlightFilter()
        {
            InitializeComponent();

            using (FlightServiceClient fsc = new FlightServiceClient())
            {
                foreach (string s in fsc.getCountries())
                {
                    cb_a_land.Items.Add(s);
                    cb_v_land.Items.Add(s);
                }

                foreach (string s in fsc.getAirPlaneClasses())
                    cb_klasse.Items.Add(s);
            }
        }