if (isset($_COOKIE[$po_cookie])) {
    $session_id = pg_escape_string($_COOKIE[$po_cookie]);

    $res = pg_query($dbh, "SELECT identifier, type, preferences, username, first_name, last_name, password
                             FROM users
                            WHERE session_id='$session_id'");
    if (($res != FALSE) && pg_num_rows($res)) {
        $row = pg_fetch_assoc($res);
      $po_user['id'] = $row['identifier'];
      $po_user['type'] = $row['type'];
      $po_user['session'] = $session_id;
      $po_user['prefs'] = $row['preferences'];
      $po_user['username'] = $row['username'];
      $po_user['first_name'] = $row['first_name'];
      $po_user['last_name'] = $row['last_name'];
      $po_user['password'] = $row['password'];
    }
  }