I can't open the file at the moment, but most calls are done in one of two ways. One: the code is added to the clip event of the button or movieclip. Two: The code is added to the main timeline and an instance name is provided to the button. If you provide an instance name for the button or menu object, then you can have a function that waits until the button is pressed. Here is an example

If my button's instance name is 'googleBtn', then I would have the following lines of code sitting on the main timeline, usually in its own layer.

PHP Code:
googleBtn.onPress = function(){
   getURL("www.google.com","_blank");
}