add posted by field on posts

I have multiple authors that post content to my website. I'd like it to show which users posts each post, but unfortunately using the gamestation theme, the only thing it shows at the bottom of a post is Posted in Video | No comments. | July 27, 2014 "

is there anyway to include "by User X" or whoever something in that field (preferably after "Posted in ___)?

a post from my site, for reference: http://www.bustedcontrollers.com/video-call-of-duty-ghosts-death-chat-12/

Hi!
Our theme doesn't support this feature, but you can add the code:

echo get_the_author();
to the file theloop.php. For example, you can replace the following string:
Posted in &nbsp;<?php the_category(', '); 

with:

Posted in &nbsp;   <?php the_category(', '); echo( ' by ' ); echo get_the_author();

never got around to thanking you for the help on this one. cheers!