PO Approval Name and Date

I have below code working for STANDARD PO and it gets the APPROVAL NAME and APPROVAL DATE.

I would like the same code to be used to get the APPROVAL NAME and APPROVAL DATE for Blanket "RELEASE". Please suggest how this can be done.

  CPD_PO_HEADERS_PRINT              table has column PO_RELEASE_ID.

SELECT  decode(:P_sortby, 'PO NUMBER', null, poh.document_buyer_last_name)
,        decode(:P_sortby, 'PO NUMBER', null, poh.document_buyer_first_name)
,        decode(:po_num_type,'NUMERIC', null, poh.po_num)
,        decode(:po_num_type,'NUMERIC', decode(rtrim(poh.po_num,'0123456789'),NULL,to_number(poh.po_num),-1), null)