Vlookup

Hello,

Im using excel 03.

Quick question if anyone can help, I have to sets of lists in column A and Column B. the basic prinicple is I have done some testing and found differences between the two columns ideally both columns should have the same data but infact they dont. in my case column B has an additional 23 pieces of data and i need to know how to use a vlookup to check what is in column A and B and what is missing from column B.

any help guys, pls??