I see that I have confused matters.
The Class Number control's Control source is Students.[Class Number] and the Row Source is a query of the Class table. You can see that in the screen shots I provided in post #10.
I called it a Combox, but perhaps that is incorrect - it's Name in Properties is "Combo274".
In post # 12, however, I was explaining how you can select students from prior classes. That is done via an unbound control, also in the header, with a label "Go to" (you can see it in the screen shots as well). Here is the Row Source query SQL:
SELECT [Students Extended].ID, [Students Extended].[Last Name], [Students Extended].[First Name], [Students Extended].[Students.Class Number], [Students Extended].[Students.Status]
FROM [Students Extended]
ORDER BY [Students Extended].[Students.Class Number] DESC , [Students Extended].[Last Name], [Students Extended].[First Name];
Let me know if this clarifies and if you have any interest in analyzing the entire database. I suspect you'd find it quite a mess as its been constructed starting last March via a lot of flailing and my trying to learn Access at the same time by reading 2 large books, doing internet searches and posting on this forum. Many things still puzzle me. I feel I might have benefited by training or tutorials that might highlight important things. If you have any recommendations on training I'd be interested.
I really appreciate your interest and apologize again for my obfuscations.