How To Make One Form Combo-box Dependent On Another?

Access 2003
Database for tracking job search/applications
I have three tables: Job (includes employer, contact) and Contact (First name, Last name, employer), and Employer (Employer name)

Form.Job is the main data entry mechanism. On this form, I enter the job details. I select the employer from a combo-box that draws from the Employer table. I would like to select the contact from a combo-box that filters contacts and shows only those that match the Job.Employer selection.

:confused: 1. How can I make a bi-directional link so that a new entry in the employer combo-box creates a new entry in the employer table? At the moment, I get around this with a "New employer" button on Form.Job that just opens up the employer table, but there seems to be an updating issue - new names don't show up in the combo-box for a while

:confused: 2. How can I get the contact combo-box to show only contacts with an employer that matches the employer selected in the employer combo-box?

Note that I got this to work once by using a sub-form, but I don't really understand how (presumably Access defaults that did what I wanted), and I don't want to have to use a sub-form.

Ben