private void lstSalesOrder_SelectedIndexChanged(object sender, EventArgs e) { if (!(lstSalesOrder.SelectedIndex < 0)) { int param = 0; //Convert.ToInt32(lstPurchaseOrder.SelectedValue.ToString()); Int32.TryParse(lstSalesOrder.SelectedValue.ToString(), out param); TransactionData.DataSource = GeneralMethods.GetSalesOrderTransaction(param); dgvSalesOrdersTransactions.DataSource = TransactionData; } }