where to add include file so that it can be seen by other files in app?

Hi,

I want to use include directive to add files into my application.

Where should I put them in order to be seen in the entire app?

I've tried in a class like this:
package org {

public class Test {
public function Test() {

include "myFile.js";

but "A file found in a source-path can not have more than one externally
visible definition.".

Thanks,
Cristina