Add "original source" link

I have searched this and no one has ever had a straight answer.
I am working on my new site Teknue.com and it is basically a tech news site, but I have plans that will make it different. But! for the time being we do news and must credit the source.

Right now I have a custom field named “Source: “, and then to the right of that you can obviously add your value. from what im reading i would have to add this to single.php in the loop

$customField = get_post_custom_values("Source: ");
if (isset($customField[0])) {
    echo "Source: ".$customField[0];
}

However in my single.php I don’t see it.

<?php get_header(); ?>
 <?php include (TEMPLATEPATH . '/top.php'); ?>
 <div class="ct_w">
	<div class="ct">
	<?php
	if($post_type == "gallery") {
		include (TEMPLATEPATH . '/gallery-single.php');
} else {
		include (TEMPLATEPATH . '/single_left.php');
		include (TEMPLATEPATH . '/single_center.php');
		include (TEMPLATEPATH . '/single_right.php');
}}
?>
	</div>
</div>

<?php get_footer(); ?>

and my index looks like this.

<?php get_header(); ?>

	<?php include (TEMPLATEPATH . '/top.php'); ?>
	<div class="ct_w">
		<div class="ct">
			<?php include (TEMPLATEPATH . '/left.php'); ?>
			<?php include (TEMPLATEPATH . '/center.php'); ?>
			<?php include (TEMPLATEPATH . '/right.php'); ?>
		</div>
	</div>
<?php get_footer(); ?>