Problem passing Parameters to SWF file

I got a really newbie question.

I want to open a .swf file with a parameter for instance test.swf?beer=good and set "good" (the "good" parameter is going to constantly change) as a variable in the script so that I can add it to the stage in the swf file. The problem is I can't seem to figure out how to read the parameter so that it can be placed in the script.

For instance I have it set to:

var beer = "";

on (release) {

getURL("http://www.google.com/search?&q="+ beer  , "_self");

}

Can anyone please help me or maybe point me to a help file/ tutorial how to do it?

Thanks in advance

//Rob