// To save additional calls to the database, return early if the user
    // doesn't have the required permissions.
    $map = array('view' => 'view any revisions', 'update' => 'revert any revisions', 'delete' => 'delete any revisions');
    $map1 = array('view' => 'view ' . $type . ' revisions', 'update' => 'revert ' . $type . ' revisions', 'delete' => 'delete ' . $type . ' revisions');
    if (isset($map[$op]) && (user_access($map[$op]) || user_access($map1[$op]) || user_access('administer nodes'))) {
    }
    else {
      $access[$node->vid] = FALSE;
      return FALSE;
    }


Stuart thin