contact referrals

[joeaverage]

Using Version 4.5.0h (Build 1239)

How can I add a "referred_by" field to Sugar that is a list of either leads or contacts to the contact page? I want to be able to track who referred who so we can determine the best leads..

I tried to add custom fields but I could never find a DB field that was the "contact" field. This should be painfully easy, but I'm totally lost.

I just want a field in each contact that is called "referred_by" and has a drop-down list or equivalent of other contacts (and/or leads).

Thanks,

-Joe