Creating a Form

Can't figure out how to do something.
I have two tables:

TblCrew
cCrewID PK Auto#)
cFName
cLName
cCrewTypeID Numberlinked to TblCrewType

TblCrewType
ctCrewTypeID PK Auto #)
ctType text

When I create a Form Using cFName, cLName and cCrewTypeID HOW can I make the
box for cCrewTypeID display whats in ctType?

cCrewTypeID is an auto Number and is assigned to each ctType BUT on a form I
dont want to see 1 or 5 I would like to see the type/text behind it like
Carpenter.

I tried look up combo box and I can see the ctType but when I select it
nothing happens since cCrewTypeID is set to accept only numbers and not text.

How can I go around that?
Thank You.