Need Help Tracking the Site Owner

[d-woo]

When the owner of a site that I'm working on logs in, he does so through a password protected directory and accesses an private/index.php file.

I want for visitors that are reading his message board via the file "board/showboard.php" to know when he is on-line, i.e. when there is a hit to the file "private/index.php" within 10 minutes of his logging on.

Would I use $http_referer to do this?

What is the simplest/best approach here?

[Anon]

Make it register into the database that he is on.

Then just select from the database and if he is ON, echo it. Else echo it not.