Sorry to post again.
In ECC 6.0 i have to reject a Purchase Requisition in the transaction ME54N.
When i am rejecting a PR in ME54N an event in Business object type BUS2105 called 'Rejection_start' is getting triggered. There are two more event in this business object 'Rejected' and 'Rejected_stop'. This is the root cause of my doubt.
Will PR be rejected by just pressing the Reject button in the transaction ME54N or there is some more to be done.