Compare records in two tables

[skilly2000]

Hi

I would like to write procedure to compare Record (Col D - INT value) in Table A and compare with Record in Table B (Col G - INT value).  if records match then i would like to update the Record in Table A (Col L) with int value 

Not sure if its best to write Stored Procedure or Function?

TIA

[#2]

That's to less on information.
Please post table design as DDL, some sample data as DML statement and the expected result.

Olaf