Looking for the best way to make sure that the user is pasting an image as a jpg, and not some other format.

Was looking at creating a validation calculation and parsing out GetAsText (YourContainerField), but was seeing if there was an easier solution.

I think you solution is both workable and excellent, this is how I used your idea in the container fields own valiadation:

PatternCount ( GetAsText ( aContainer ) ; ".jpg" )

--sd

Sounds good. Thank you. Although I have to deal with the ugly revert record message, and unfortunately the user makes several other changes to the record before leaving so they lose all changes.

You could provide a script for pasting (or entering data in any other way), and include the validation in the script.

Yes, I think that, that will be the cleanest and most professional way of doing it. I will just create a Insert Picture Button.