Navigation for single form view

I have a form that works best in single form view (it's too big and unwieldy
for continuous view) displaying several records (all from the same table)
about various suppliers that my company uses. What i would like to do is set
up some form of navigation, either in the form of a drop-down list of company
names, allowing the user to jump to a given record without having to know the
record number, or some form of sidebar, like a navigation frame in an html
website. I've tried doing this with a combo box which looks up fields from a
list of suppliers from a separate table, but I can't figure out how to make
it control which record the form looks at. Am I barking completely up the
wrong tree here? Any thoughts on how i might best achieve this would most
gratefully received.

Cheers,

Jake
.