private void btnBorrow_Click(object sender, EventArgs e) { if (dtpBorrowed.Value < dtpDue.Value) { CirculatedCopy cc = new CirculatedCopy(); cc.CopyNumber = int.Parse(txtCopyNumber.Text); cc.MemberNumber = int.Parse(txtMemberCode.Text); cc.BorrowedDate = dtpBorrowed.Value; cc.DueDate = dtpDue.Value; if (CirculatedCopyDAO.Add(cc)) { Copy c = CopyDAO.GetCopy(int.Parse(txtCopyNumber.Text)); c.Type = 1; CopyDAO.UpdateType(c); display(2); view(int.Parse(txtMemberCode.Text)); MessageBox.Show("Add Successful."); if (check == 1) { Reservation r = ReservationDAO.GetFirstReservation(c.BookNumber); r.Status = true; ReservationDAO.UpdateStatus(r); } if (dgvBorrowedBooks.Rows.Count >= 5) { display(0); MessageBox.Show("The number of borrowed books is 5. You can not borrow anymore book."); } } else { MessageBox.Show("Error."); } } else { MessageBox.Show("Borrowed date has to be smaller than Due date."); } }