private void GenerateGRN(object sender, EventArgs e)
        {
            if (_view.headSeleted.ReceiptHeaderId == 0)
            {
                MessageBox.Show("Please save this receipt before generate GRN.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                return;
            }

            if (!_view.headSeleted.GenReceiptNumberFlag)
            {
                POReceiptHeaderModel rcv = _view.headSeleted;
                rcv.ReceiptNum = _repository.GenGRN("RECEIVING_PO", rcv.ReceiptDate);
                if (rcv.ReceiptNum != "")
                {
                    rcv.GenReceiptNumberFlag = true;
                    _repository.UpdateRcvHead(rcv);

                    _view.headSeleted = rcv;
                }
                else
                {
                    MessageBox.Show("Cannot generate GRN.", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    return;
                }
            }
        }