WP plugin_no_upgrade

add_filter('option_update_plugins', 'plugin_no_upgrade');function plugin_no_upgrade($option){    $this_plugin = plugin_basename(__FILE__); //eg: 'nextgen-gallery/nggallery.php'    if( isset($option->response[ $this_plugin ]) ){        //Clear its download link:        $option->response[ $this_plugin ]->package = '';    }    return $option;}