Thumbnail

<?php if(has_post_thumbnail($post->ID, 'thumbnail')):
$image_id = get_post_thumbnail_id($post->ID);
$image_url = wp_get_attachment_image_src($image_id, 'thumbnail', true); ?>
<a href="<?php echo get_permalink($post->ID) ?>" class="post-thumb"><img src="<?php echo $image_url[0]; ?>" alt="<?php echo $post->post_title ?>" /></a>
<?php endif; ?>