I found the answer myself, zhanks:
You have to add this:
<?php if ($preview = get_post_meta($post->ID, ‘preview’, $single = true)) { ?>
<p>ID, “imglink”, true); ?>”><img src=”<?php bloginfo(‘stylesheet_directory’); ?>/timthumb.php?src=<?php echo $preview; ?>&h=245&w=440&zc=1″ alt=””/>
<?php } else { ?>
The strong one connects the new custom field called ‘imglink’ with the ‘preview’ one and hands over the forewarder url.
Take care and share!
Love to all of You around mother earth
greetings from the top of the Black Forest! which seems to be the hottest place today: close to 40+ celsius