Help with loading JSON file from cross-domain URL

Hi,

I need to load a JSON file from my server, but it needs to work in any domain.

I read this on manual:

[quote:2xij83vw]If you want AJAX requests to your server to work from any domain, or in preview, you can configure it to send the following HTTP header:

Access-Control-Allow-Origin: *

This will enable AJAX requests from any domain

But this is not clear for me. How I can configure it? In my searches i find about a php header

header('Access-Control-Allow-Origin: *')[/code:2xij83vw] But how i can add this HTTP header in a JSON file?