Add a variable to PHP output

Hello folks,
The title to this may be misleading… but, I will get right to the point.

I have a Flash swf that is set up to send variable to a PHP script which, in turn adds the information to text file (.txt) in a guestbook that needs to be read by another flash movie.

Everything is working. I know this… but… in order to make it more flexible, I need the PHP to add a variable that I set, at the beginning of the text document. Right now, the text displays great if I send it to the flash file by calling on the PHP… but I would rather have the text file load into the flash directly… to get it to work, I need to add a variable…

this is what the php is sending (example)
$Input = “Info: $Information”;

So what I need to do is add something like
theVariable=

this will allow me to load the text file without the php (as there are some limitations)

I tried adding the variable to the text file by adding it like this:
$Input = “theVariable= Info: $Information”;

which writes the words “theVariable=” to the file, thus allowing me to read it in the other flash file.

however, the php script is “adding” to the text file, so that it keeps getting bigger, like a guestbook… so… If I use the above method, every new entry will start with my variable, but will only display the most recent entry.

Any ideas?

Thanks in advance… sorry for the long winded explaination…
r