I think as I sit here and ponder, I will attempt to use Ajax to call a controller method that will write the data to the database, then return the primary key and hide it in the form. This way when the users return to complete the form, instead of writing a new record, it will use the primary key to update the existing record. And if the application has logged the user out, then when the user returns to the form, the application will check to see if a record already exists. If yes, it will retrieve the partially saved data, otherwise, the form will have blank fields.

This has been a great exercise in thought. Thanks for your help!