public string NewSigId(string defaultNewId, DataRow dataSourceRow)
{
    DataSet ds = Api.Zselect(MercatorUi.Globals.RepData, "select isnull(max(s_id),'500000') from stock where (s_id>='500000') and (s_id<='599999')");
    if (ds == null)
        return "";
    Int64 new_s_id = 1 + Convert.ToInt64(ds.Tables[0].Rows[0][0]);
    if (dataSourceRow.Table.Columns.Contains("increment"))
        new_s_id += Convert.ToInt32(dataSourceRow["increment"]);
    return new_s_id.ToString();
}