Popup message if no record is updated

[Matt]

I have a form with a subform that requests users to input data via drop-down
boxes and text boxes.

However, if none of these boxes are updated, I would like a pop-up message
to appear asking the user to fill out at least one of the boxes. Or if they
don't know, to select don't know from the last tab called, "Feedback" on my
subform. Until something is filled out or "I don't know" is selected, the
user should not be able to access the next record.

How would I do that? Thanks in advance for your help.

 

[Matt]

Any chance I can get some help on this issue? If you need more detail,
please let me know.

Thanks,
Matt

 

[Linq Adams via AccessMonster.com]

Proving that a change has been made to a record or that a new record has been
created is easy, but you're trying to prove a negative here, something that
is difficult to do.

Is there never a case where the user would simply want to look at a record?
Because that is essentially what you're saying; if a record is viewed it has
to be altered.