Syntax error

Hi there! Even though I’m not “new” with wordpress, this is the first time I try to modify a theme. So far I could manage to make some codes work, but when I mix them thogheter I got syntax errors.

This is the situation:
I wanted to show a list of post of the category before the content of the “active” post itself; so I searched in the forum for a code wich would let me do that.
Once I found it I manage to make it work while showing the post, but when I add all the rest of the code (wich includes the comments and the pagenav – starts in the div “postmeta”) I get those syntax errors!
Please, if somebody can help me out it would be really appreaciated!

Here is the code of “single.php”:

<?php get_header(); ?>

<div id="singContent">

<?php
global $post;
$categories = get_the_category();
$category = $categories[0];
$cat_ID = $category->cat_ID;

$myposts = get_posts("numberposts=0&category=$cat_ID&order=ASC&orderby=date");
?>
<ul class="sing">
<?php foreach($myposts as $post) :?>
<li class= "sing">
<a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></li>
<?php endforeach; ?>
</ul>
</div>

<div id="coreContent">
<?php the_post() ?>
 <div class="post single hentry">
        <div class="postContent">

          <div class="entry-content">
              <?php the_content(); ?>
          </div>
        </div>
        <div class="postMeta">
          <?php
          $arc_year = get_the_time('Y');
          $arc_month = get_the_time('m');
          $arc_day = get_the_time('d');
          ?>

          <div class="postDate"><span>Published:</span> <abbr class="published" 

title="<?php the_time('Y-m-d\TH:i:sO'); ?>"><a href="<?php echo 

get_day_link("$arc_year", "$arc_month",
          "$arc_day"); ?>"><?php the_time('F j, Y'); ?></a></abbr></div>
        	<div class="categories"><span>Filed Under:</span> <?php 

the_category(', '); ?></div>
        	<?php the_tags('<span>Tags:</span> ', ' : ', ''); ?>
        </div>
	  </div>

        <div class="postMeta">

        <?php if ('closed' == $post->comment_status) : ?>

          <div class="comments closed">

         	<?php else : ?>

          <div class="comments">

          <?php endif; ?>

            <?php comments_popup_link('leave a comment', '1 comment', '% comments', 

'', 'comments closed'); ?>
          </div>
        </div>
      </div>

		<?php endwhile; ?>

    <div class="pageNav">
      <div class="prev"><?php next_posts_link('< Older Posts') ?></div>
      <div class="next"><?php previous_posts_link('Newer Posts >') ?></div>
    </div>

	<?php else : ?>

		<h2>Not Found</h2>
		<p>Sorry, but you are looking for something that isn't here.</p>

	<?php endif; ?>

  </div>

<?php get_footer(); ?>