add this to your functions.php
add_theme_support( 'post-thumbnails' );
set_post_thumbnail_size( 50, 50, true ); // Normal post thumbnails
add_image_size( 'single-post-thumbnail', 400, 9999 ); // Permalink thumbnail size
// THIS LINKS THE THUMBNAIL TO THE POST PERMALINK
add_filter( 'post_thumbnail_html', 'my_post_image_html', 10, 3 );
function my_post_image_html( $html, $post_id, $post_image_id ) {
$html = '<a href="' . get_permalink( $post_id ) . '" target="_parent" title="' . esc_attr( get_post_field( 'post_title', $post_id ) ) . '">' . $html . '</a>';
return $html;
}
put this where ever you want the thumbnail
<?php the_post_thumbnail(); ?>
Put this on your single post
<?php the_post_thumbnail( 'single-post-thumbnail' ); ?>