what about you
[php]
function wpbeginner_postrss($content) {
if(is_feed()){
$content = 'This post was written by Syed Balkhi '
.$content.'Check out WPBeginner';
}
return $content;
}
add_filter('the_excerpt_rss', 'wpbeginner_postrss');
add_filter('the_content', 'wpbeginner_postrss');
[/php]
