integrate login forms for phpBB into a pre-existing website.

Simple job - I have an existing website using PHP 4.4.4 and MySQL 4.1.21 with a simple register/login form. Recently, users wanted to integrate a phpBB forum, but I don't want them to have to login to the site as well as the fourm (instead there should be a single log-in that works for both). I want to take the phpBB register/login form, and integrate it into the already existing site, as a replacement for the old system. I will also need a simple way for users to access certain areas of the site when (and only when) they are logged in and the login screen must be replaced with a link system that allows users to access account settings and other useful areas after the user has logged in. If you are not already familiar with phpBB, it is an free, open source forum script that uses PHP and MySQL. The pages in phpBB use PHP template files (wherein the layout of the page is kept on a seperate file from the actual scripts that run it), which makes it easy for users to select different "forum skins" while they are using the forum. This is an easy project, and shouldn't take more than a day or two to finish. -ryan