private void txtdiscond_KeyDown(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Enter) { if (order.VERIFY_QNT(txtproduct.Text, Convert.ToInt32(txtqnt.Text)).Rows.Count < 1) { MessageBox.Show("هذه الكميه غير متاحه", "تنبيه ", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } for (int i = 0; i < DGPRODUCTORDER.Rows.Count - 1; i++) { if (DGPRODUCTORDER.Rows[i].Cells[0].ToString() == txtproduct.Text) { MessageBox.Show("هذا المنتج تم ادخاله", "تنبيه ", MessageBoxButtons.OK, MessageBoxIcon.Warning); return; } } DataRow DR = dt.NewRow(); DR[0] = txtproduct.Text; DR[1] = txtproductname.Text; DR[2] = txtprice.Text; DR[3] = txtqnt.Text; DR[4] = txttotalprice.Text; DR[5] = txtdiscond.Text; DR[6] = txttotalamount.Text; dt.Rows.Add(DR); DGPRODUCTORDER.DataSource = dt; ClearBoxes(); TXTsumtotals.Text = (from DataGridViewRow row in DGPRODUCTORDER.Rows where row.Cells[6].FormattedValue.ToString() != string.Empty select Convert.ToDouble(row.Cells[6].FormattedValue)).Sum().ToString(); } }