private void cboIssuedTo_SelectedValueChanged(object sender, EventArgs e) { if (cboIssuedTo.SelectedValue != null) { DataTable dtItem = new DataTable(); Items itm = new Items(); int duId = Convert.ToInt32(cboIssuedTo.SelectedValue); dtItem = itm.GetItemsByDU(duId); PopulateItemListByDU(dtItem); } }