Blank Data in BPM

I created a BPM to send email when DRM disposition = RTV, however, I'm not able to include any information for the DRMheader into the email message (Ex. PartNumber, Vendor, ...).

my BPM as following:
there is at least one added row in the ttDMRActn table
and the DMRActn.ReasonCode field of the added row is equal to the 'RTV' value

and Action:
send e-mail asynchronously based on the rtv template

I need any one points me to the right direction.

Thank you.
Lam