How to show just parent category, no child, help

Hi, I have this loop in my category-7.php

I would like to return just parent posts, and this below is my code which is broken… neeeeed help from some gurus here 🙂 thx

<?php if (have_posts()) : ?>

	<?php while (have_posts()) : the_post();
        if ( in_category(7) && post_is_in_descendant_category(7) ) {
    ?>
		<div <?php post_class() ?> id="post-<?php the_ID(); ?>">

			<div class="post-headline">
				<h2>
					<a href="<?php the_permalink() ?>" rel="bookmark" title="stalni link na <?php the_title_attribute(); ?>"><?php the_title(); ?></a>
				</h2>
			</div>
		    <div class="post-byline"><?php the_time("F jS, Y") ?> - <?php the_author() ?></div>
			<div class="post-bodycopy clearfix">
				<?php if the_content(" .. opširnije &raquo;"); ?>
			</div>
		</div>

	<?php } ?>
	<?php endwhile; ?>

<?php if ( is_single() ) { comments_template(); } ?>

<?php else : ?>

	<h2 class="center">Ups..</h2>
	<p class="center">sorry, izgleda da nisam nasao sta trazis.</p>
	<?php get_search_form(); ?>

<?php endif; ?>

this function ‘post_is_in_descendant_category’ is in my theme folder functions.php, and I copied it from here http://codex.wordpress.org/Function_Reference/in_category

.k