public override void buttonAdd_Click(object sender, EventArgs e) { MainClass.Enable_Reset(panelRightSlider); comboBoxSelectProduct.Enabled = false; textBoxQuantity.Enabled = false; textBoxTotalCost.Enabled = false; textBoxProdCost.Enabled = false; textBoxPONumber.Enabled = false; textBoxUnit.Enabled = false; DataTable dt = new DataTable(); // dt = retrieve.GetId("usp_GetPOID", comboBoxSelectProduct.Text); //PoNumber = Convert.ToInt32(dt.Rows[0][0].ToString()) + 1; //textBoxPONumber.Text = PoNumber.ToString(); textBoxPONumber.Text = retrieve.RetrunPoNumber().ToString(); }