Setting up usernames in R12

Summary

Use person number as username when employee has no email

Content

Hi -

We currently have the system configured to generate usernames based on email addresses.  If a user does not have an email address the system generated username is the firstname.lastname of the employee.  Is there a way to have this default to the person number instead of firstname.lastname?

I checked out documents in support but can only find document How Fusion Application Generate Default User Name For Newly Created User? (Doc ID 1680835.1) which is not for R12.

Thanks,

Roy