Referral System need help!

[robotx21]

Ok, I have a referral system set up on Access, but I need help with automating part of it. Each person gets a number when placed into the database. This is the referral number. Here is my setup:

Date Ordered: (Date)
First Name: (Name)
Last Name: (Name)
# of Referrals: (sum # of people this person has referred)
Referred by: (the user's ID# whom referred this person)
User ID#: (this person's unique ID#)
Users Referred: (User ID #'s this person has referred)

Each person will get a database filled out with this information. I need help automating the User ID's. Example:
1st DATA ENTRY

Date Ordered: 1/13/05
First Name: Joe
Last Name: Shmoe
# of Referrals: 0
Referred by: None
User ID#: 001
Users Referred: None

2nd DATA ENTRY

Date Ordered: 1/15/05
First Name: John
Last Name: Doe
# of Referrals: 0
Referred by: 001 <<--- I input this
User ID#: 002
Users Referred: None

This is what I want to be updated automatically on entry #1

Date Ordered: 1/13/05
First Name: Joe
Last Name: Shmoe
# of Referrals: 1
Referred by: None
User ID#: 001
Users Referred: 002

The bold is what I want to be automatically updated. Any help will be greatly appreciated!