If you need an 'undo' feature, the typical thought that comes to my mind is:

   1. make a *before* copy of the data
   2. let the user make changes to the data
   3. if changes were made, ask the user if
      he/she wants to keep those changes
   4. if user wants to keep changes, move or
      copy the new data to the *current* data

      if user does not want to keep changes, move
      or copy *before* data to *current* data
[download]

That's kind of a simplistic method, but I think it achieves the goal. Is that what you were looking for?

Hope this helps.