Tracking class using cookies

<?php

/* PHP Tracker class. Version shithouse 0.2 lol
 * Evan Harrison 2012
 */

class tracking {

    var $cookievar;

    public function start_cookie($cookievar) {
    if (isset($_COOKIE)) {
        if ($_COOKIE[$cookievar] == '') {
        tracking::create_cookie($cookievar, $_SERVER['HTTP_REFERER'], time() + 3600);
        //echo "This is a new cookie";
        } else {
        $this->cookievar = $_COOKIE;
        }
    }
    }

    private function create_cookie($name, $ref, $expire) {
    if (isset($_SERVER['HTTP_REFERER'])) {
        $this->cookievar = setcookie($name, $ref, $expire);
    } else {
        // code to handle no referer here
    }
    return true;
    }

    public function output($cookievar) {
    if (isset($_COOKIE[$cookievar])) {
        $success = $_COOKIE[$cookievar];
    } else {
        $success = "<p>No cookie of that name found.</p>";
    }
    return $success;
    }

    public function destroy_cookie($cookievar) {
    $cookievar = setcookie($cookievar, "", time() - 3600);
    return $cookievar;
    }

}

?>