array method attributes (OO)

I wish to pass a session variable into an object and have it available as an attribute. I have what I thought I needed below as a code segment but it douse no work. Has anybody got any idea how I should achieve this. Ben ...... class Contacts{

        var $db;
        array $SESSION;

        function Contacts( $SESSION, $db ) {

                $this->$SESSION = $SESSION;
                $this->$db                      = $db;

        }

...... ****************************************************************

* Ben Edwards           Tel +44 (0)1179 553 551  ICQ 42000477  *

* Homepage - nothing of interest here http://gurtlush.org.uk *

* Webhosting for the masses         http://www.serverone.co.uk *
* Critical Site Builder    http://www.criticaldistribution.com *

* online collaborative web authoring content management system * * Get alt news/views films online http://www.cultureshop.org *

* i-Contact Progressive Video      http://www.videonetwork.org *
* Fun corporate graphics             http://www.subvertise.org *
* Bristol Indymedia               http://bristol.indymedia.org *
* Bristol's radical news             http://www.bristle.org.uk *

****************************************************************