protected void lstCompany_SelectedIndexChanged(object sender, EventArgs e) { DataTable dt = objCompBLL.Get_CompanyRelationships(UDFLib.ConvertToInteger(lstCompany.SelectedValue), GetSessionUserID()); foreach (ListItem li in lstCompany1.Items) { DataRow[] dr = dt.Select("child_company_id = " + li.Value + " and relation =" + ddCompRelationshipType.SelectedValue); if (dr.Length > 0) { li.Selected = true; } else { li.Selected = false; } } }