Problem trying to have "Older posts link" on archive.php custom template

Hi, i’m new to the forum, i’m just stuck trying to “getpagenavi” declared on functions.php to work.

I specifically need it on the archive.php, this is my code:

<?php get_header(); ?>

<div>&nbsp;</div>
<div>&nbsp;</div>
<div class="subhead">
	<div class="insubhead">
		<?php if (have_posts()) : ?>

		 <?php $post = $posts[0]; // Hack. Set $post so that the_date() works. ?>
<?php /* If this is a category archive */ if (is_category()) { ?>

 	  <?php /* If this is a daily archive */ } elseif (is_day()) { ?>
		<h1 class="pagetitle">Archivo de <?php the_time('F jS, Y'); ?></h1>

	 <?php /* If this is a monthly archive */ } elseif (is_month()) { ?>
		<h1 class="pagetitle">Archivo de <?php the_time('F, Y'); ?></h1>

		<?php /* If this is a yearly archive */ } elseif (is_year()) { ?>
		<h1 class="pagetitle">Archivo de <?php the_time('Y'); ?></h1>

	  <?php /* If this is an author archive */ } elseif (is_author()) { ?>
		<h1 class="pagetitle">Archivo por Autor</h1>

		<?php /* If this is a paged archive */ } elseif (isset($_GET['paged']) && !empty($_GET['paged'])) { ?>
		<h1 class="pagetitle">Archivos del Blog</h1>
		<?php } ?>
	</div>

</div>
<div class="right">

<div class="featbox"><h3 class="sidetitl"></h3><pre>
<?php // code goes here

?>
</pre>
 <?php $video = get_option('repo_video'); echo stripslashes($video); ?></div> </div>
<div id="content" >

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

<div class="postarch" id="post-<?php the_ID(); ?>">
<div class="title">
<h2><a href="<?php the_permalink() ?>" rel="bookmark" title="Permanent Link to <?php the_title(); ?>"><?php the_title(); ?></a></h2>
</div>

<div class="postmeta" width=755px; height=55px;>
	 <span class="clock">  <?php the_time('M - j - Y'); ?></span> <span class="comm"><?php comments_popup_link('0 Comentarios', '1 Comentario', '% Comentarios'); ?></span> <span class="category">Categorias: <?php the_category(', '); ?> </span>
</div>
<div class="entry">

<?php
if ( has_post_thumbnail() ) { ?>
	<img class="postimg" src="<?php bloginfo('stylesheet_directory'); ?>/timthumb.php?src=<?php get_image_url(); ?>&h=120&w=160&zc=1" alt="" />
<?php } else { ?>
	<img class="postimg" src="<?php bloginfo('template_directory'); ?>/images/dummy.png" alt="" />
<?php } ?>

<?php wpe_excerpt('wpe_excerptlength_blurb', ''); ?>
<div class="clear"></div>
</div>

</div>

<?php endwhile; ?>

<?php getpagenavi();?>
<?php else : ?>

	<h1 class="title">Inexistente</h1>
	<p>Disculpe, la categoria que busca no se encuentra aqui.</p>

<?php endif; ?>

</div>

<?php get_sidebar(); ?>
<?php get_footer(); ?>

I just don’t know to make it work, if someone has some code or plugin answer? Would be awesome, thanks in advance!