merge multiple worksheets
 

I have two worksheets, both of which are very similar. As a matter of fact
they started out as the same worksheet, someone copied them, and two users
were making their own changes to these sheets. Now I have to put them back
together and show the changes that both users made. The sheets are saved in
different workbooks, and they are not shared books. There are upwards of
three thousand rows in these sheets, and sixteen columns. Is there an easy
way to go about this?