Passing variables to flash

So, I read the tutorial about passing variables by changing the url of the .swf with the following code:

if (movie==1 or movie=="") {
   trace("default");
}
if (movie==2) {
   getURL("http://www.yahoo.com");
}

My question is, is there anything special if I want it to respond to the url of a .php page? So, if I have a page that ends in “?page_id=2” could I do the same thing or does it have to be an .swf?

if (page_id==1 or page_id=="") {
   trace("default");
}
if (page_id==2) {
   gotoAndPlay("pageTwo");
}