There is a better way - you can also use this function too -
function catch_that_image() {
global $post, $posts;
$first_img = '';
ob_start();
ob_end_clean();
$output = preg_match_all('/<img.+src=[\'"]([^\'"]+)[\'"].*>/i', $post->post_content, $matches);
$first_img = preg_replace("/_thumb[0-9]\./", "$1.", $first_img);
// no image found display default image instead
if(empty($first_img)){
$first_img = "/wp-content/default.png";
}
return $first_img;
}
if you insert this function to your functions.php of your theme you can insert
<img src="<?php echo catch_that_image(); >" width="50" height="50" alt="<?php the_title(); ?>" />
in your single.php and index.php
This function will catch the first image in ever post and will display it, if no one is available - it will use one Default image which you can change...
Or another way:
<?php $image = get_post_meta($post->ID, 'postimage', true); ?>
<img src="<?php echo $image; ?>" alt="<?php the_title(); ?>" />
If you put this in your index.php or single.php it will use the image given in field "postimage" (customfield in posts/pages).
I hope this helps