Thank you both for the suggestions. I suspect I have no Control-L because I
work only with VB with Access, not the full program, but thanks anyway Tim.
And I haven
't bothered to learn how to use the locals or watch windows. Anyway, Dirk,
you said it could not be done, so I took Tim's suggestion and put breakpoints
on the first line of every procedure, function and event on that form and
found the problem. The answer surprised me.

The form is for employees and has an up and down arrow to move up the list
of managers and back down to where you started. However, at the top, where
the employee and the manager are equal, I disable the up arrow. When you
click on the disabled up arrow again the form header executes a tab to tab
one, not the next tab in the list. Well this moves the focus to the manager's
field, which was calling the function with what I thought was a wrong
variable. I reorganized the tab list so the up and down arrows are one and
two and now when you click on the disabled up arrow, it tabs to the down
arrow and the manager's got focus never executes. Problem solved be using a
lot of breakpoints and following the bouncing ball. Thanks for your help.
Regards,
Michael