private void bnChangeData_Click(object sender, EventArgs e)
{
Book newBook = new Book(tbNameBook.Text,
tbAuthor.Text,
tbPublishingHouse.Text,
tbPublishingYear.Text,
tbDescription.Text,
Int32.Parse(lbID.Text));
var returnText = presenter.ChangeBookInfo(newBook);
MessageBox.Show(returnText);
}
