show approve by to manager in asp.net

i want to show
when supervisor approve document
like hr supervisor approve hr documents then hr manager able to view that
who approve document i.e approve by
 
here is sp
when i enter this
sphrdoc2 1
it shows me

Docid	docname	document	approvetype	department	fileuploaded	approveid
20	hosting	msword	3	finace	abc.docx	pending
21	attock	msword	1	finance	def.docx	approve

then i want to add one more column i.e approve by