get post images to link to external sources

Question

I'm buiding a site that lists the most recent posts on the front page, the site is a recompilation of interesting articles and images so it doesn't make sense to link to the individual post.

I currently have the title redirecting externally to the link, but I would also like to link externally via the post image.

I've set up a custum field "externalurl"

This is what I have so far in the loop.php which does not work:

    <?php
    if ( has_post_thumbnail() ){ ?>
        <?php $thumbURL = get_post_custom_values('externalurl'); ?>
        <a href="<?php echo get_attachment_link($thumbURL); ?>" rel="gallery" title="<?php the_title(); ?>">        
            <?php the_post_thumbnail(); ?>
            <span class="view-large"></span>
        </a>
    <?php } ?>

Does anybody have any idea what I'm doing wrong? Any suggestions welcome.

Thanks in advance!

Answer 1

http://codex.wordpress.org/Function_Reference/get_post_meta

wouldn't echoing get_post+meta in the a link be best?

<a href="<?php echo get_post_meta($post->ID, "externalurl", true) ); ?>" rel=...and so on