Wordpress example that retrieves child pages and outputs them

page.php

<?php

query_posts(
	array(
		'showposts' => 20, 
		'post_parent' => $page_id, 
		'post_type' => 'page', 
		'order' => 'ASC'
	)
); 

$i = 0;

while (have_posts()) : the_post(); ?>
	<?php $slug = basename(get_permalink()); ?>
    <div id="<?php echo $slug; ?>" class="pane">
		<div class="content">
			<div class="inner">
				
				<h2 class="title"><?php the_title(); ?></h2>
            	
            	<?php the_content(); ?>
            	
        	</div>
        
		</div>
    </div>
	
<?php $i++; ?>
<?php endwhile; ?>