I am trying to protect which .js files are available based on the domain name a user is accessing the server from.

There are multiple sites that are the same but have slightly different .js files.
None of the sites are suppose to see the .js files that are supposed to "belong" to other domains.

Let's say Site1.com can access js1.js and only that .js
if a web-inspector/fire-bugger knew of the site's nature (unlikely, but I'm a programmer, so ofcourse i'm paranoid) they could include js2.js on Site1.com because they all point to the same server.

I have very very little experience with apache/.htaccess.
I think I got "pretty urls" to work once... like once. in a very simple way.

But from what i uunderstand apache/.htaccess is hit before php or js or any file on the server.
So maybe there is a way to say "if domain is Site1.com" then don't allow access to js2.js.