Add vendor name field in MB5B (ZMB5B)

Hi to every body.

i am working i a small company for the maintenance of project in mm module.

at present i am modifying the mb5b report.

in that i was asked to add extra field for vendor name.

for that i am using lfa1 table. but vendor name is not show in my report out put

plz help me how to add field vendor name??

Regards,

Richa