why this Related post by category not working in my theme

base on this site

I just only copy paste this code

<?php $orig_post = $post;
global $post;
$categories = get_the_category($post->ID);
if ($categories) {
$category_ids = array();
foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;
$args=array(
'category__in' => $category_ids,
'post__not_in' => array($post->ID),
'posts_per_page'=> 5, // Number of related posts that will be displayed.
'caller_get_posts'=>1,
'orderby'=>'rand' // Randomize the posts
);
$my_query = new wp_query( $args );
if( $my_query->have_posts() ) {
echo '<div id="related_posts" class="clear"><h3>Related Posts</h3><ul>';
while( $my_query->have_posts() ) {
$my_query->the_post(); ?>
<li>
 <a href="<?php the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>">
 <?php the_post_thumbnail( 'related-posts' ); ?>
 </a>
 <div class="related_content">
 <a href="<? the_permalink()?>" rel="bookmark" title="<?php the_title(); ?>"><?php the_title(); ?></a>
 </div>
</li>
<? }
echo '</ul></div>';
} }
$post = $orig_post;
wp_reset_query(); ?>

to display related post by category but this error appear
Parse error: syntax error, unexpected T_ENDIF in C:\xampp\htdocs\mm\wp-content\themes\mm\single.php on line 46

can somebody have an idea………