Select a category to print

I need to print post of cat=5 and I need to modify this part of code but Im not a programmer:

<?php $wp_query = new WP_Query(array('cat'=>of_get_option('category_blog'),'showposts'=>of_get_option('postnumber_blog'),'paged'=>$paged)); ?>
<?php if($wp_query->have_posts()) : while($wp_query->have_posts()) : $wp_query->the_post(); ?>
<?php global $more; $more = 0; ?>

I try to add this:
<?php query_posts('cat=5'); ?>
but it doesn’t work.
Anyone can help me?

Regards