Reg: Purchase order no from accounting document no

hi,

I have to generate a report of vendor billing details,where i have to get the corresponding purchase order no for accounting document no.From bseg i am getting the ebeln field but i have fetched based on posting key bschl ='86' or '81'.for the corresponding document no.Without this can i get the ebeln from another table.

'Docu.Dt', 'Posting Dt', 'Bline Dt', 'Docu.No', ' Purchase Or.No'

from,

Dinamol