[AccessD] Prompt to save changes on form with multiple subforms

I have a form that is used to setup billing parameters and fees.  This form
has multiple subforms on a tab control with each subform handling  different
fee types and how those fees are setup.  The subforms are all showing in
datasheet view.

I now have a request to prompt the user if they want to save their changes
(if they have made any) before they close the main form.  They don't want to
be prompted after each record change, only after they have made their
changes in each subform and possibly multiple records in each subform.

The only idea I have so far is to populate a tempory table with the
oldvalues of the fields they change, then when they go to close the main
form, if there are entries in the changes table, prompt them if they want to
keep the changes, if not, build a SQL statement based on the values in the
temporary table and run it to set the values back to the originals.  Does
this sound feasible or is there a better way?

TIA

Rusty
rusty.hammond at cpiqpc.com