Order posts by ID ?

change it to
$readposts = get_posts(‘category=13&orderby=ID’);

see also
https://codex.www.ads-software.com/Template_Tags/get_posts

Thanks for the reply. Still not working for me ??
Here’s my code:

<?php

$readposts = get_posts('category=13&orderby=ID');

?>

	<dl>

	<?
    foreach($readposts as $post) : setup_postdata($post);
    ?>

				<dt><a href="#"><?php the_title(); ?></a></dt>

				<dd>
					<ul>
						<li><img src="<?php
$supporting_image=get_post_meta( $post->ID, 'thumbnail', true );
if (''!=$supporting_image)
{
  echo $supporting_image;
}
?>" alt="<?php the_title(); ?>" style="float:left;padding-right:20px;" />
<?php the_content() ?></li>
					</ul>
				</dd>

    	<?php
    	endforeach;
	?>

	</dl>

</div>

<?
endif;
?>

It keeps it in the same order ?? Any other ideas?

sorry about the delay, when you say it keep[s teh same order, by default posts are ordered by id form newest to oldest, how do you want them ordered?

If you want oldest first, add order=ASC to that. Like so:

$readposts = get_posts(‘category=13&orderby=ID&order=ASC’);