Changing Fields

Hey there, I need to know how to do someting. I've written an employee database. One of the things I want employees to do is to be able to update their information as it changes (address, last name, ss# or whatever). On the record editing page, all the fields that they are allowed to modify are there. When I update the record, all fields are updated. Most of the time they 're updating only a couple of fields. I want to be able to send an email to our HR department and notify them only about the fields that have changed. Since all the fields are actually in the update statement, how would I be able to tell what information had changed and what had not? Thanks, Marky