private void BorrowBookButton_Click(object sender, EventArgs e) { if (tableStatus == TableStatus.All) { var row = BooksDataGridView.Rows[currentIndex]; var idBook = int.Parse(row.Cells[0].Value.ToString()); var idSubscriber = idCurrentSubscriber; service.AddBorrowedBook(new BorrowedBook(idBook, idSubscriber)); if (int.Parse(row.Cells[4].Value.ToString()) == 1) { service.DeleteBook(idBook); } else { var book = new Book(int.Parse(row.Cells[0].Value.ToString()), row.Cells[1].Value.ToString(), row.Cells[2].Value.ToString(), row.Cells[3].Value.ToString(), int.Parse(row.Cells[4].Value.ToString()) - 1); service.UpdateBook(book); } ClearLabels(); DisplayBooks(); } else { MessageBox.Show("You can't borrow a borrowed or reserved book!"); } }