Posts pagination

Hello,

I want to divide my post in several pages (https://codex.www.ads-software.com/Styling_Page-Links ) I’ve add the tag et I’ve put <!–nextpage–> in HTLM mod in the post I want to be divised.

But I’ve got a problem, the template where my posts are divided is totally messed up. The right sidebar is now below the content.

Here’s the code from my single.php :

<div class="entry">
    <!-- google_ad_section_start(weight=medium) -->
    <?php the_content(''); ?>
	<!-- google_ad_section_end -->
<?php wp_link_pages(); ?>

    <div class="clear"></div>
    <div class="postmeta"> <strong>Filed in:</strong>
      <?php the_category(',');?><br />
      <?php the_tags('<span>Tags:</span> ', ', ', ' '); ?>
      <?php edit_post_link('Edit', '[ ', ' ]'); ?>
    </div>
    <!--end: postmeta--->
  </div>
  <!--end: entry-->
  <div class="postnav">
    <div class="left">
      <?php previous_post_link('%link', '<div class="previouspost">&laquo; Previous</div>%title', TRUE);  ?>
    </div>
    <div class="right">
      <?php next_post_link('%link', '<div class="nextpost">Next &raquo;</div>%title', TRUE); ?>
    </div>
    <div class="clear"></div>
  </div>
  <!--end: postnav-->
  <?php comments_template(); ?>
  <?php endwhile; else: ?>
  <h2 title="h2title">
    <?php _e('Not Found', 'themejunkie'); ?>
  </h2>
  <div class="entry">
    <?php _e('Sorry, the post is not exists.', 'themejunkie'); ?>
  </div>
  <!--end: entry-->
  <?php endif; ?>
</div>
<!--end: content-->
<?php include('post-sidebar.php'); ?>
<?php get_footer(); ?>

Thanks you for your help.

Best regards