[SOLVED] post - custom field

Hi, I am kind of a novice to website programming but first of all I want to state my thanks to all those knowledged once and the developers of this gorgeous theme!!!!!
i am just trying to start off to accostomize this theme to my personal "liking" and I initially thought it would be easy but all my attempts have been unsuccessful. I tried to search google without avail so some here might be my help.

I have a custom field named postthumb with the direction of a thumbnail, which contains the following value:

postthumb - /gallery/tr_at_vienna/thumbs/thumbs_vie_001.JPG

Under
centercolumn->style and edit center column -> the loop (this is all in the admin scetion) I introduced the following section to reference the image (in bold):

************

<?php /* Post Container starts here */
if ( function_exists('post_class') ) { ?>
<div <?php if ( is_page() ) { post_class('post'); } else { post_class("$odd_or_even"); } ?> id="post-<?php the_ID(); ?>">
<?php } else { ?>
<div class="<?php echo ( is_page() ? 'page ' : '' ) . $odd_or_even . ' post" id="post-'; the_ID(); ?>">
<?php } ?>


<div class="post-magazin">
<div class="post-left">

<img src="<?php bloginfo('url'); ?>/wp-content<?php get_post_meta($post->ID, 'postthumb', true); ?> ">

</div>

<div class="post-center">

..............


unfortunately, the image never shows up and I cannot figure out why? Any Ideas? The first part, ie the Url, I can see in firebug but not the rest!

Thanks in advance to anybodys' help!!!!!!!!!!!!!!!!!!

Isa