reverse order in a query

Okay here goes!

On my index page i use multiple categorys.
I use this code:

<?php $recent = new WP_Query(); ?>

            	<?php $recent->query('cat=6&showposts=12'); ?>

            	<?php while($recent->have_posts()) : $recent->the_post(); ?>
                <div id="date"><?php the_time(' j F Y') ?> van </div><div id="time"><?php the_content(); ?></div>

                <?php endwhile; ?>

But now i have to reverse the order only on this category.

i read somewhere to use this code:

<?php query_posts($query_string . "&order=ASC") ?>

but i dont know how/where to place this.