adding text box from table

[Michael]

Access 2000
ok. i have a form that adds records to a table
(tblHdwChange)
this table has a relationship with 3 other tables for a
combo boxes.
i have created a new table that has records that will have
a relationship of 1(tblHdwPerJob) to Many(tblHdwChange)
which i want to add a text box in the form to show a value
for the correct relationship with the information selected
in the form. I am not sure if I set up the relationship
correctly. Here's the problem, the record that has the
correct information that i want in the text box has to
match two combo boxes from the form. A double
relationship, if that exists in databases. Do I set up
the relationship with tblHdwChange(2 relations), or with
the tables that produce the information for the combo
boxes.
I tried to add this text box and it stays empty.
When I edit the record source to add a relationship
between the two tables(double relation), the text box in
the form does show the information correctly, but the form
shows the first record from tblHdwChange and i cannot add
new records, but it is supposed to be a data entry form
and was before.
Is any of this making sense?
Any ideas on what I did wrong?
Thanks for any help.