Session in a flash

[Cazz]

I have search here and I cant find that I looking fore.

I use much ASP and sometime I use session.
Now I try to find that in flash

That I try to do is this, I like to have a session in a flash that remember if the flash have show the visiter the movie.
The problem is that if the visitor is new the flash is going to play, after that that going to show a button if the visitor like to see the movie one more time.
The visitor going to surf around the site can maybe come back to the flash and the visitor is going to see the button (The flash have already play one time before)

If the visitor close the browser I whant that session to disappear so if the visitor visit the page again immediate the movie i play automatic and then again save the session so the movie dont show again so long the visitor is there and dont have close the browser.

The page that flash is going to be is a clean HTML so no ASP/PHP/Javascript


I going to be very happy if someone can help me whit this problem

(Sorry if that is hard to read my messenger, I'm not so good to write english)