How to compare data in two sheets?

[Novice09]

Hi Friends,

I need to compare some data by using excel 2007.

There are two excel sheets and both contains some users and their data in following format:

Sheet1:
Column a : user name
columm b : 1, 2, 3, 4, 5 (data in single cell)

sheet2:
Column a : user name
columm b : 1, 5, 2, 6 (data in single cell)

Now I have to extract those values which are missing in sheet2 column b and which are extra in sheet2 column b by comparing it with sheet1. Example:

Missing data : 3, 4
Extra data : 6