private void AddBook_Click(object sender, RoutedEventArgs e)
        {
            var vb = new Program.BookView();

            if (vb.ShowDialog() == true)
            {
                bookGrid.Items.Refresh();
            }
        }
        private void bookGrid_MouseDoubleClick(object sender, MouseButtonEventArgs e)
        {
            var vb = new Program.BookView((Book)bookGrid.SelectedItem);

            if (vb.ShowDialog() == true)
            {
                bookGrid.Items.Refresh();
            }
        }