Navigation code not working on Single Post view

Hi there!

I’m the webmaster for the Domino Girls webcomic (https://www.dominogirlscomic.com), and I use WordPress to do it. To make it easier to read the comic, I created a navigation bar. Here’s the code I use:

<div class="navigation">
			<div class="alignleft"><?php next_posts_link('&laquo; Previous Entries') ?></div>
                        <div class="alignleft">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="https://www.dominogirlscomic.com/2007/02/01/">First Comic</a></div>
                        <div class="alignleft">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<a href="https://www.dominogirlscomic.com">Today's Comic</a>&nbsp;&nbsp;&nbsp;&nbsp;</div>
			<div class="alignright"><?php previous_posts_link('Next Entries &raquo;') ?></div>
		</div>

All the links appear as expected on the main index page, but when on the Single Post view (the one where you go when you click on the title of the post), only the First Comic and Today’s Comic links appear.

Can anyone tell me how to fix this?

Lisa Hartjes