Add Author to Post information in the Loop

I've been trying to figure out how to add "Author" as part of a typical blog post's description in the RetroPress Theme. In theloop.php, I've even tried aping the 'category' heading, but nothing appears when I add it in. Here is the relevant code:

<?php 
	global $post, $query_string, $SMTheme;
	query_posts($query_string);
	$i=1;
	if (have_posts()) :  
	
	if (!isset($_GET['ajaxpage'])) {?>
 <div class='articles'>
	<?php }
	while (have_posts()) : the_post(); 
	?>
		<div class='one-post'>
		<div id="post-<?php the_ID(); ?>" <?php post_class("post-caption"); ?>>
			<?php if (!is_single()&&!is_page()) { ?>
			<h2><a href="<?php the_permalink(); ?>" title="<?php printf( $SMTheme->_( 'permalink' ), the_title_attribute( 'echo=0' ) ); ?>" class='post_ttl'><?php the_title(); ?></a></h2>
			<?php } else { ?>
				<h1><?php the_title(); ?></h1>
			<?php } ?>
			<p><?php if (!is_page()) {?><span class='post-date'><span class='day'><?php echo get_the_date('d'); ?></span><br /><span class='month'><?php echo get_the_date('M'); ?></span></span>

        <!-- Author Info -->
<img alt="" src="<?php echo get_template_directory_uri();
?>/images/smt/category.png">Author:&nbsp;<?php the_author(',&nbsp;'); }?>

 <img alt="" src="<?php echo get_template_directory_uri();
?>/images/smt/category.png">Category:&nbsp;<?php the_category(',&nbsp;'); }?>
			<?php if(comments_open( get_the_ID() ))  {
                    ?><img alt="" src="<?php echo get_template_directory_uri(); ?>/images/smt/comments.png">Comments:&nbsp;<span class="meta_comments"><?php comments_popup_link( $SMTheme->_( 'noresponses' ), $SMTheme->_( 'oneresponse' ), $SMTheme->_( 'multiresponse' ) ); ?></span>