Old && New Values For My Activity Log ??

I have a requirment to create a activity log to log all changes that
take place in my tables as they happen. All my Inserts,updates & Deletes take place inside stored procs. A windows .NET application calls the stored procs and passes the data set to the stored procs to execute them on a Sql server 2000 database.

When an update statement is run inside my stored proc, the dataset only passes me the new values. but,i will need the old value from the database before the update takes place to report in my activity log. What is the best way to do it ?

My activity log shold report a description like this

"Name Changed from 'Robert Johnson'(old value) to 'Bob Johnson'(New Value)"


Though i can do a select from the tables to get the old values and match the new values to get the differences before running the update statements, it is too much work as i have well over 100 stored procs in my application and i have to check for every single field value in a table. If only one column changed in a table containg 20 columns, i would still have to check for 20 columns before determining which fields changed.

Can any one suggest me a better solution to report the old values and new values for all the updates that take place in a database through stored Procedures.

Thanks
Reo