private void Cancel(object sender, RoutedEventArgs e)
        {
            MainWindow  main            = Application.Current.MainWindow as MainWindow;
            brokersList brokersListPage = new brokersList();

            main.frame.Navigate(brokersListPage);
        }
        private void Delete(object sender, RoutedEventArgs e)
        {
            db.brokers.Remove((brokers)dgBrokers.SelectedItem);
            db.SaveChanges();
            MainWindow  main            = Application.Current.MainWindow as MainWindow;
            brokersList brokersListPage = new brokersList();

            main.frame.Navigate(brokersListPage);
        }
        private void BrokersList_Click(object sender, RoutedEventArgs e)
        {
            brokersList brokersListPage = new brokersList();

            frame.Navigate(brokersListPage);
        }