Comments breaks my layout

I downloaded a theme from CSS-Tricks.com and installed on my site. It's not a perfectly build theme but I like the layout so much that I continue using it.

But, when it comes to comment section, it only showed 1 comment and then break the layout. You can see it on this page the sidebar was gone.

How to fix this? Anyone can help me?

This is the code for comment.php

<?php // Do not delete these lines
    if ('comments.php' == basename($_SERVER['SCRIPT_FILENAME']))
        die ('Please do not load this page directly. Thanks!');

    if (!empty($post->post_password)) { // if there's a password
        if ($_COOKIE['wp-postpass_' . COOKIEHASH] != $post->post_password) {  // and it doesn't match the cookie
            ?>

            <p class="nocomments">This post is password protected. Enter the password to view comments.</p>

            <?php
            return;
        }
    }

    /* This variable is for alternating comment background */
    $oddcomment = 'class="alt" ';
?>

<!-- You can start editing here. -->

<?php if ($comments) : ?>
    <h3>Comments</h3>

    <ol class="commentlist">

    <?php foreach ($comments as $comment) : ?>

        <li <?php echo $oddcomment; ?>id="comment-<?php comment_ID() ?>">
            
            <div class="comment-bubble">
                <?php if ($comment->comment_approved == '0') : ?>
                    <p>Your comment is awaiting moderation.</p>
                <?php endif; ?>
    
                <?php comment_text() ?>
            </div>
            
            <img src="/images/bubbletip.png" alt="" style="margin-top: -10px;" />
            
            <img src="<?php gravatar("R", 40, "http://css-tricks.com/wp-content/themes/CSS-Tricks/images/missing-gravatar.png"); ?>" alt="Gravatar" class="gravatar" />
            
            <?php comment_author_link() ?>
            
            on <?php comment_date('F jS, Y') ?> at <?php comment_time() ?>
            
        </li>

    <?php
        /* Changes every other comment to a different class */
        $oddcomment = ( empty( $oddcomment ) ) ? 'class="alt" ' : '';
    ?>

    <?php endforeach; /* end for each comment */ ?>

    </ol>

 <?php else : // this is displayed if there are no comments so far ?>

    <?php if ('open' == $post->comment_status) : ?>
        <!-- If comments are open, but there are no comments. -->

     <?php else : // comments are closed ?>
        <!-- If comments are closed. -->
        <p>Comments are closed.</p>

    <?php endif; ?>
<?php endif; ?>


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

<h3 id="respond">Leave a Reply</h3>

<?php if ( get_option('comment_registration') && !$user_ID ) : ?>
<p>You must be <a href="<?php echo get_option('siteurl'); ?>/wp-login.php?redirect_to=<?php echo urlencode(get_permalink()); ?>">logged in</a> to post a comment.</p>
<?php else : ?>

<form action="<?php echo get_option('siteurl'); ?>/wp-comments-post.php" method="post" id="commentform">

<?php if ( $user_ID ) : ?>

<p>Logged in as <a href="<?php echo get_option('siteurl'); ?>/wp-admin/profile.php"><?php echo $user_identity; ?></a>. <a href="<?php echo get_option('siteurl'); ?>/wp-login.php?action=logout" title="Log out of this account">Logout &raquo;</a></p>

<?php else : ?>

<p><input type="text" name="author" id="author" value="<?php echo $comment_author; ?>" size="22" tabindex="1" />
<label for="author">Name <?php if ($req) echo "(required)"; ?></label></p>

<p><input type="text" name="email" id="email" value="<?php echo $comment_author_email; ?>" size="22" tabindex="2" />
<label for="email">Mail (will not be published) <?php if ($req) echo "(required)"; ?></label></p>

<p><input type="text" name="url" id="url" value="<?php echo $comment_author_url; ?>" size="22" tabindex="3" />
<label for="url">Website</label></p>

<?php endif; ?>

<!--<p><strong>XHTML:</strong> You can use these tags: <code><?php echo allowed_tags(); ?></code></p>-->

<p><textarea name="comment" id="comment" cols="60" rows="10" tabindex="4"></textarea></p>

<p><input name="submit" type="submit" id="submit" tabindex="5" value="Submit Comment" class="button" />
<input type="hidden" name="comment_post_ID" value="<?php echo $id; ?>" />
</p>
<?php do_action('comment_form', $post->ID); ?>

</form>

<?php endif; // If registration required and not logged in ?>

<?php endif; // if you delete this the sky will fall on your head ?>

PHP:

 

Anyone can help here?

 

<b>Fatal error</b>: Call to undefined function gravatar() in <b>/home/astronyu/public_html/wp-content/themes/PersonalHomepageTheme/comments.php</b> on line <b>41</b><br />


That is where the problem lies. That is an invalid image and there is no such image on their servers.

 

Thank you sir, the layout was fixed.
+1 to your reputation.

 

Thanks for the rep. Great to know that it fixed your problem.