Wordpress Themes - WP Forum at BFA - dynamic resizing of picture on category-page?

I have made a custom categorypage (its my first, so don't laugh too much if the code is somewhat clumsy...), and need the image I have there to resize dynamic like the images on other pages.

I have understood its the .post & img.size-full -classes that takes care of this, but I cant get it working on the categorypage? I have copied the code for the img from a page where it is working correctly, so this is really bugging me...

Here is the code for my categorypage:

PHP Code:


		
			
<?php

/*

Template Name: sporsmal-og-svar

*/

?>

<?php     /* get all options: */

include (TEMPLATEPATH . '/functions/bfa_get_options.php');

get_header(); ?>

<div class="post-headline"><h2>Spørsmål & svar</h2>

</div>

<div class="post-bodycopy clearfix"><p><img class="alignnone size-full wp-image-692" title="150310_mb_060_2_" src="http://domain.ext/wp-content/uploads/2010/05/150310_mb_060_2_.jpg" alt="" width="720" height="500" /></p>

<?php query_posts('cat=3'); ?>

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

        <a class="spmsvar" href="<?php the_permalink(); ?>"><h3><?php the_title(); ?></h3>

        <p><?php the_excerpt(); ?> --> Les svaret</p></a>

<?php endwhile ?>

</div>

<?php endif; ?>

<?php get_footer(); ?>

Any help to get this working would be nice! :)