public static void ShowBuyDialog(LogisticData db)
        {
            var win = new BuyCarWindow();

            win.db = db;
            win.CitiesComboBox.ItemsSource  = db.GetCities();
            win.CarTypeComboBox.ItemsSource = db.GetCarTypes();
            win.ShowDialog();
        }
        public static void ShowMakeOrderDialog(LogisticData db)
        {
            var win = new MakeOrderWindow();

            win.db = db;
            win.CitiesFromComboBox.ItemsSource = db.GetCities();
            win.CitiesToComboBox.ItemsSource   = db.GetCities();
            win.CarTypeComboBox.ItemsSource    = db.GetCarTypes();
            win.ShowDialog();
        }