classes?

ok all i'm just starting to get involved with classes...and have a slight problem......i don't understand how to access functions..i have been reading the manual at php.net but that confuses even more....take a look at some code i wrote... print "<a href=\"$PHP_SELF?product=$product&quanity=1\">$title - $price</a>"; thats to add a item to my cart...... the class function looks like this...

        function add_item($table, $session, $product, $quantity) {
            $qty = $this->check_item($table, $session, $product);
            if($qty == 0) {
                $query = "INSERT INTO $table (session, product, quantity) VALUES ";
                $query .= "('$session', '$product', '$quantity') ";
                mysql_query($query);
            } else {
                $quantity += $qty;
                $query = "UPDATE $table SET quantity='$quantity' WHERE session='$session' AND ";
                $query .= "product='$product' ";
                mysql_query($query);
            }
        }

my question is how to i pass that vars that i need to the class? am i making sense here? ~kurth Kurth Bemis - Network/Systems Administrator, USAExpress.net/Ozone Computer There is no sin except stupidity. -- Oscar Wilde kurth@usaexpress.net | http://www.usaexpress.net/kurth PGP key available - http://www.usaexpress.net/kurth/pgp Fight Weak Encryption! Donate your wasted CPU cycles to Distributed.net (http://www.distributed.net)