How to personalise flash movies?

This is a viral email where you can type your freinds name and email address into a text box (in this case at the end of the movie). Then the link to the above flash movie is sent to their email account (i’m guessing the id equals their name).

About two thirds through the movie the name of your freind gets displayed in the flash movie in a hand written font on a piece of paper.

Its a really good piece of personalised viral emailing, you even get follow up mails sent to your inbox, but how is it done?

Any clues or pointers would be gratefull received!

I’ve got a feeling its something to do with pulling in data from an xml file but i’m not sure how you can add the users name to the xml file in the first place let alone get flash to read it!