private void searchCustomer_TextChanged_1(object sender, KeyEventArgs e) { if (e.KeyCode == Keys.Enter) { try { int customer = Convert.ToInt32(searchCustomer.Text); CustomerDebt customerDebt = CustomerDebt.getCDebt(customer); DebitSale debitSale = DebitSale.getDebitSale(customer); if (customer == null) { MessageBox.Show("The debt information of the customer entered was not found!", "ERROR"); } else { List <DebitSale> debtSoldProducts = DebitSale.getallDSale(); if (debtSoldProducts != null) { foreach (DebitSale s in debtSoldProducts) { Object[] SoldProducts_debt = { s.customer_no, s.product_no, s.CustomerDebt.debt_amount, s.sale_date, s.sale_no, s.payment_method, }; table.Rows.Add(SoldProducts_debt); } } } } catch (Exception EX) { MessageBox.Show(EX.Message, "ERROR"); } } }