Creating recordsets

First, my database is split into both a front and backend.  Record locking is enabled for edited records - also enabled record-level locking.  The main form is bound to a table, and has one subform that is also bound to a different table.  I have designed the database so that the user cannot create or move to a new record (there is a separate form for this purpose).  When a change is made to the subform, I change the main forms .tag property to "DIRTY".  When user moves to a different record, if main form is dirty, or if the forms .tag property = "Dirty", user is prompted to save changes.  If no, me.undo rolls back changes on main form.  

There is a major flaw to this design.  Changes on subform do not roll back if user chooses to not save record. Subform is a datasheet to which user may have several new added records.  I need to undo each of these changes as well.

I think a solution might be when each user (up to 15 at any given time) opens the form, i unique recordset is created rather than bind the forms to tables (Can you bind a form to a recordset?). Then, when prompted to save the changes, use code to write all values from the recordset to the their respective tables or just close the recordset if decision is to not save. How would I do this?

One problem I can foresee; without a bound form, the on dirty property is nix. If using the recordset rather that the form, how can I trigger a prompt to save if changes are made?