public AdminForm(FrontForm front)
        {
            try
            {
                Locations   = SaveLoad.LoadAirports();
                Fleet       = SaveLoad.LoadFleet();
                Flights     = SaveLoad.LoadFlights();
                AllAirports = SaveLoad.LoadAllAirports();
            }
            catch (FileNotFoundException ex)
            {
                MessageBox.Show(ex.Message);
            }

            Front = front;
            InitializeComponent();

            //the first panel to be displayed
            FlightPanel flightPanel = new FlightPanel(Flights, Fleet, Locations);

            //displaying method with inputed panel
            AddControls(flightPanel);
            btnFlight.BackColor = SystemColors.Control;
            btnFlight.Enabled   = false;
        }
        private void btnFlight_Click_1(object sender, EventArgs e)
        {
            FlightPanel flightPanel = new FlightPanel(Flights, Fleet, Locations);

            AddControls(flightPanel);
            btnFlight.BackColor  = SystemColors.Control;
            btnAirport.BackColor = Color.SteelBlue;
            btnFleet.BackColor   = Color.SteelBlue;
            btnFlight.Enabled    = false;
            btnFleet.Enabled     = true;
            btnAirport.Enabled   = true;
        }