Wordpress在保存帖子/页面时更新作者Meta

How can I update author meta data while save a post/page? Any ideas?

function update_author_data_too($order){

$author_id = 468;   
$new_site = 'http://wordpress.org'
update_user_meta( $order->user_id, 'user_url', $new_site);

}

add_action( 'save_post', 'update_author_data_too' );

Any ideas why that does not work?