Need Form Combo Box to Populate Table

[EastIndian]

Beginner Question - I know I'm missing a key step, but not sure what it is...

I've got two tables. The main table contains a foreign key field called PAYMENT. The second table contains a the primary key (autonumber) for each payment type, cash or check:
pkPmtType Type
1 Cash
2 Check

I have created a query to link the two and make a combo box on a form:
SELECT tblPayment.pkPmtType, tblMain.fkPmtType
FROM tblPayment INNER JOIN tblMain ON tblPayment.pkPmtType = tblMain.fkPmtType;

On the form, the combo box displays the text for the payment type and works great except I am unable to get my selection to populate the main table with the primary key for payment type when I save the record. I know there must be a relatively simple solution that I am not aware of. Any help would be very much appreciated!
Thank you!

 

[EastIndian]

Sorry to answer this myself--I figured out that my form combo boxes were not bound to the table--I knew it had to be something simple. Thanks anyway!