I've trying to build Joomla into my existing website so I can use it for premium content.

I've already got a custom-built authentication system that sets my own session variables.

For some reason, Joomla (which is located in a different directory) doesn't want to recognize these session variables, even when adding the session_start(); line at the top of all Joomla pages.

Any idea how I can get Joomla to recognize my custom session variables so I can limit the content located in Joomla to only premium users?

Thank you.