I'm working on making a form more user friendly -
What I'd like to do is to link multiple fields and to narrow selections in
field2 and field3 based off of what a user selects in field1.

Example:
I have field1 Principal with 10 options.
I have field2 PrimaryCategory with 20 options, however, there are only 2
valid options per Principal.
I have field3 Brand with 50 options, however, there are only 2-5 valid
options per Principal.
Right now, all options for field2 and field3 show up in the combo box
regardless of what is chosen in field1.
What I'd like is once user makes selection in field1, for field2 and field3
to automatically show ONLY the valid options for that specific selection in
field1.

Is this possible? Can anyone give me a starting point for figuring out how
to set this up? Would an ifthen statement work here - and if so, do I put
that in the code on field2 and field3?

I'm working in both Access 2003 and 2007, depending on if I'm doing the work
at the office or at home.

I appreciate any help!