Event question/code streamlining

[Stephanie]

Hello. I would really love help streamlining code - any takers!?
In any case, I can't seem to get the functionality I want to work when I
want it to.

Here's the scenario: Contacts certify with Animals. Once certified
together, Animals (read-only) show on the Individuals main form. Then the
Contact/Animal team can be assigned to volunteer on a subform (of
Individuals) called sfrmExtraService3.

On this subform, I have 2 combo boxes:
cboVolunteering is based on VolunteerID, VolunteerDate, VolunteerName (the
event), OrganizationName...

cboAnimals based on info pertinent to the Animal, with the pull down on
AnimalName.

The process is to select the VolunteerDate (cboVolunteering) and then the
AnimalName (cboAnimal). That way the code (in theory) checks the
certification date against the volunteering date.

Here's the issue: if I don't choose a VolunteerDate, cboAnimal shows the
correct animal- those certified to the Contact. If I do choose a
VolunteerDate, cboAnimal is blank. And worse, if I leave the record and
return, cboAnimal is still blank. I actually have to close the form and
reopen it in order for cboAnimal to return the correct certified Animal for
the Contact. Hardly handy.

So, am I missing a requery of cboAnimals on sfrmExtraService3 or a requery
of sfrmExtraService3 itself on Individuals? And what Event should I be using?

Thanks- I do appreciate the expertise of the user group!