Sign ups, how to?

Hi guys.

At school I’ve been given a task where I’m supposed to make a flash website for some sort of course. My problem is that the imagined “visitors” at my website are supposed to be able to sign up and been given a random contestant number (1, 2, 3, 4 etc). This number must later on be remembered so that it can be used to sort out different information regarding these participants.

(It’s about a fishing contest. People gotta sign up, they’re given a number, and later on I need to use that number to weigh the supposed fishes they’ve gotten and stuff. I think I can handle the last part on my own, I’m just not sure how to make this random number generator that saves the amount of people participating in a list or an array or something.)