Okay, I wrote this really cool function, you see. It populates tons of blank
cells for the end-users, saving them hour upon hours of time. Everyone's
happy....except....

The function updates a bunch of data, but the "Undo" button is never
activated. So, if the want to undo the data changed by my way-cool function,
the only way for them to do it is to close the file without saving changes
and re-open it.

How do I get my code to activate the "Undo" button, so the changes can be
rolled back if needed?

Thanks!