Merging Salesids in one field

static void CopyDataMergeSalesIds(Args _args)
{
    ASAP_DeliveryNoteHeader    headerTable;
    ASAP_DeliveryNoteLines     lineTable;

    ANA_DeliveryListTmpHist    mainTable,sourceTable;

    ASAPG_DeliveryNote         previousId;

    Str1260                    salesIds;

    Name                       reportiD;
    str                        salesId;

    select mainTable where mainTable.ReportId == "DN-ASAP0000004" ;
    {
        reportiD = mainTable.ReportId;
        while select sourceTable where sourceTable.ReportId == reportiD
        {
            salesId +=", "+sourceTable.SalesId;
        }
        info(strFmt("%1 -- %2",reportiD, subStr(salesId,2,150)));

    }


}

output
DN-ASAP0000004 --  SO-ASAP008337, SO-ASAP008338, SO-ASAP008338, SO-ASAP008339, SO-ASAP008340