Recruitment registration codes?

[lvletei]

Okay, I know this will probably be something simple, but I don't know how to figure it out. If this has been posted elsewhere, please delete this and I'll search again lol. To my question, I'm making a website for an xbox live clan, and for the registration, I don't want it to be open registration, I want it to be: Someone already in the clan sends a code to the person they're recruiting, they enter that code in the registration form to validate that they have been added to the clan roster, then they proceed with registration. I have no idea what to do for that, so if someone could help any bit at all it would be most appreciated 😃

[Krik]

Well a question then arises where does this code come from? To validate the new registration based on that code requires that the code to be accessible to PHP.

This can be done a few ways. Either have an automated script that when a clan member clicks a button it generates a random code and stores it in a database. Or you can assign a code (that is stored in the database) to each user when they sign up. Or just have one set in stone for everyone.

Of course if you have static codes over time you risk them becoming spread around to the degree that is risk you may want to use dynamically generated codes. There are some tutorials around on generating a random string of characters. You will want to search for tutorials on random password generation or password recovery.