Can someone tell me why this doesn't work - custom fields

<a href="<?php the_permalink(); ?>">
<img src="<?php bloginfo(&#8216;siteurl&#8217;); ?>/bookThumbnails/<?php $key="bookPromo"; echo get_post_meta($post->ID, $key, true); ?>" border="0" />
</a>
<h2>
<a href="<?php the_permalink(); ?>">
<?php the_title(); ?>
</a>
</h2>

I have the images I am trying to display in a folder called bookThumbnails with my images in there.
inside my bookPromo custom field I have a value of teaching-critical-thinking.jpg which is the name of the file(s) that are inside the bookThumbnails folder.

Thank you.

Are you using the Thesis Theme by any chance?

no it’s the Six Hours theme.

nevermind I figured it out it should have been

<a href="<?php the_permalink(); ?>">
<img src="/wp/bookThumbnails/<?php $key="bookPromo"; echo get_post_meta($post->ID, $key, true); ?>" border="0" />
</a>
<h2>
<a href="<?php the_permalink(); ?>">
<?php the_title(); ?>
</a>
</h2>