Reset, errmm, resets the form to the values it had on page load. i.e. before the form gets submitted.
I guess it depends on where you want to change the values.
If after they submit, and on a "preview" page (before a database/filewrite commit) you could just send them back to the form.
If after a database/filewrite commit you need to save the previous values so they can be re-entered.