private void txtCustomerName_SelectedValueChanged(object sender, EventArgs e) { string CustomerName = txtCustomerName.Text; if (CustomerName != string.Empty) { txtMSKH.Items.Clear(); var listDB = customerBO.GetIDByName(CustomerName); foreach (var item in listDB) { txtMSKH.Items.Add("KH" + item.ToString("d6")); } txtMSKH.Text = "KH" + listDB.First().ToString("d6"); loadHD(); } }