Populate a slideshow list of images from images in a wordpress page?

Most of this is part of the Codex:

<?php
$attachments = get_posts(array(
    'post_type' => 'attachment',
    'numberposts' => -1,
    'post_status' =>'any',
    // This is where you specify the ID of your private image page
    'post_parent' => $private_page_id,
));

if (count($attachments)) {
    // We have attachments
    ?>
    <ul id="flexiselDemo3">
        <?php
        // Now we loop through them
        foreach ($attachments as $attachment) {
            ?>
            <li>
                <?php echo wp_get_attachment_image($attachment->ID, 'full'); ?>
            </li>
            <?php
        }
        ?>
    </ul>
    <?php
}
?>