From Flash to PHP and Back Again

Cheesy title.

I want to send Flash data to a .php. I learned how with this:

However, I want the .php to then write the variables to a .txt. That way, Flash can read the data back from the .txt. I don’t want to open any browser windows; I just want to recieve my data in Flash.

If you recommend an entirely different method, I’d be grateful for that, too. If this is the wrong forum, castigate me to the max.