List pages with attached image

Hello,

I’m trying to create a simple image based page navigation that consists out of

– the page title
– the image attached to the page

and that looped for all the children of a page.

But I just can’t figure it out.

What I have so far is:

<?php
echo '
<ul>';
// Get a list of pages
$children = get_children('post_type=page&post_parent=26');

// Loop over each page
foreach ($children as $child) {
// Get the attached image url
$thumbnail = wp_get_attachment_url($post->ID);
// Print to screen
echo '<li class="page_item page-item-'. $child->ID .'"><a>ID .'" href="?page_id='. $child->ID .'"><img src="'. $thumbnail .'">'. $child->post_title .'</a>';
}
echo '</ul>
';

?>

Anybody any thoughts?