Previous/Next page link on wordpress not working

My previous/next page link on wordpress not working.

[edwinteguh]

Would you help me because I'm really confused.
My previous/next page link on wordpress not working. When I click, just refresh again at similar result page.
Would you assist me how to solve my problem?
Thank you very much

Below is my full index.php

<?php
get_header();
?>

<div id="content">
<?php webhosts(); ?>

<?php $count = 0;?>
<?php query_posts('showposts=4'); ?>
<?php if (have_posts()) : ?>

<?php while (have_posts()) : the_post(); ?>

<div class="postindex" id="post-<?php the_ID(); ?>">

<h2><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2>

<div class="entry">
<?php the_excerpt(__('Readmore »'));?>

</div>
<div class="spacer"></div>
<ul class="post-data">
<li class="comments">
<?php comments_popup_link('No Comments &raquo;', '1 Comment &raquo;', '% Comments &raquo;'); ?>
</li>
<li class="posted">
<?php the_time('F jS, Y') ?> by <?php the_author() ?> <?php edit_post_link('Edit','',''); ?>
</li>

</ul>
</div>

<?php comments_template(); ?>
<?php
if($count == 1 ) {
echo "<div style='clear:both;'></div>";}
$count = $count+1;
?>

<?php endwhile; else: ?>
<p><?php _e('Sorry, no posts matched your criteria.'); ?></p>
<?php endif; ?>

<?php posts_nav_link(' &#8212; ', __('&laquo; Previous Page'), __('Next Page &raquo;')); ?>

<?php get_footer(); ?>

Thank you very much for your advance.

[coopster]

I would start by locating the functions that build the links and debug at that point. Make sure the links are being written as you expect. If not, you'll have to work your way back from there.