private void btnRegister_Click(object sender, EventArgs e)
        {
            if (ValidateChildren(ValidationConstraints.Enabled))
            {
                if (txtProductName.Text == "")
                {
                    MessageBox.Show("Please select a product name", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    txtProductName.Focus();
                    return;
                }

                if (txtQuantity.Text == "")
                {
                    MessageBox.Show("Please enter a quantity", "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    txtQuantity.Focus();
                    return;
                }
                try
                {
                    BusinessManager BM  = new BusinessManager();
                    BOProduct       BOP = new BOProduct();
                    BOInventory     BOI = new BOInventory();
                    BOP.ConfigID      = txtConfigID.Text;
                    BOI.InventoryDate = dtpInventoryDate.Text;
                    auto_generate();
                    BOI.InventoryID = txtInventoryID.Text;
                    BOI.Quantity    = txtQuantity.Text;
                    BOI.TotalPrice  = txtTotalPrice.Text;
                    bool res = BM.BALVerifyInventoryName(BOP);

                    if (res == true)
                    {
                        MessageBox.Show("Record already exists!" + "\n" + "Please update the stock of product", "Input Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                    }
                    else
                    {
                        int rowsAffected = BM.BALInsertIntoInventory(BOP, BOI);

                        if (rowsAffected > 0)
                        {
                            MessageBox.Show("Successfully saved", "Record", MessageBoxButtons.OK, MessageBoxIcon.Information);
                            btnRegister.Enabled = false;
                            getData();
                            //frmMainMenu frm = new frmMainMenu();
                            //frm.GetData();
                        }
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
                }
            }
        }