This will depend on the method you choose to restrict access. You could do it at the application level, web server level, or even the filesystem level.
At the application level youŽd determine at login time which access level the user has. Then when a request comes in youŽd check whether the userŽs access level is high enough to be granted access to the requested resource.
At the webserver level you could use AuthGroupFile [httpd.apache.org] and AuthUserFile [httpd.apache.org] to tell [url=http://httpd.apache.org/]Apache [httpd.apache.org][/url] about your users and groups and then Require [httpd.apache.org] the right user or group to access a directory.
At the fs level you could use a setuid wrapper script that will assume the required identity to access its files on the server.
Andreas
