/// <summary>
/// Checks if a book has been selected and then shows bookcopies by book.
/// </summary>
/// <param name="sender"></param>
/// <param name="e"></param>
private void btnSelectCopy_Click(object sender, EventArgs e)
{
Book book = lbBooks.SelectedItem as Book;
if (lbBooks.SelectedIndex == -1)
{
MessageBox.Show("Please choose a book.");
}
else
{
ShowAllCopies(copyService.ByBook(book.Id), lbIndCopy);
}
}