Referral URL/Point system

[LocaButt]

I have a working registration/login system.  I am trying to set up a basic referral type system for a contest.

 

The user (already registered in members table) fills out the contest form, it spits out a referral URL and they share it. The person clicking the URL is taken to the contest page and fills out the form, repeating the process but gives the original user +1 point for the clicked url.

 

I have searched for hours and I am pretty sure this is just a basic referral system but I am just not understanding.  I guess my issue is pulling the info from the current members table upon submission and inserting it into the contest table. Do any of you know of any good tut's or maybe you can explain it somewhat easily?

 

Thanks for any insight.