Regular extention?

[Ad Bakker]

$tweet = $message;
return preg_replace("/#([A-Za-z0-9_]+)(?=\s|\Z)/", '<a href="'.$mybb->settings['bburl'].'/hashtag/\1">#\1</a>', $tweet);
return $message;

I don't have much experience with regular expressions but the above php code cannot be good, with 2 return stements after each other. However I suppose the 1st does the same as the 2-nd, when in the 1-sr return is replaced bby $message =