related post in wordpress

<?php
/* related post in wordpress by Category */

/* 1. add this code in functions.php */


    add_theme_support( 'post-thumbnails' );
    set_post_thumbnail_size( 150, 150, true );




/* Then add this codode in single.php */

 <div class="relatedposts">
<h3>Related posts</h3>
<?php $orig_post = $post;
    global $post;
    $categories = get_the_category($post->ID);
    if ($categories) {
    $category_ids = array();
    foreach($categories as $individual_category) $category_ids[] = $individual_category->term_id;

    $args=array(
    'category__in' => $category_ids,
    'post__not_in' => array($post->ID),
    'posts_per_page'=> 4, // Number of related posts that will be shown.
    'caller_get_posts'=>1
    );

    $my_query = new wp_query( $args );

    while( $my_query->have_posts() ) {
    $my_query->the_post();
    ?>

    <div class="relatedthumb">
        <a rel="external" href="<?php the_permalink()?>"><?php the_post_thumbnail(array(150,150)); ?><br />
        <?php the_title(); ?>
        </a>
    </div>

    <?php }
    }
    $post = $orig_post;
    wp_reset_query();
    ?>
</div>


/* 3 Some css style */
.relatedposts {width: 640px; margin: 0 0 20px 0; float: left; font-size: 12px;}
.relatedposts h3 {font-size: 20px; margin: 0 0 5px 0; }
.relatedthumb {margin: 0 1px 0 1px; float: left; }
.relatedthumb img {margin: 0 0 3px 0; padding: 0;}
.relatedthumb a {color :#333; text-decoration: none; display:block; padding: 4px; width: 150px;}
.relatedthumb a:hover {background-color: #ddd; color: #000;}






                              /* related post in wordpress by tag */


/* 1. add this code in functions.php */


    add_theme_support( 'post-thumbnails' );
    set_post_thumbnail_size( 150, 150, true );


/* 2 Then add this codode in single.php */

<div class="relatedposts">
<h3>Related posts</h3>
<?php
    $orig_post = $post;
    global $post;
    $tags = wp_get_post_tags($post->ID);

    if ($tags) {
    $tag_ids = array();
    foreach($tags as $individual_tag) $tag_ids[] = $individual_tag->term_id;
    $args=array(
    'tag__in' => $tag_ids,
    'post__not_in' => array($post->ID),
    'posts_per_page'=>4, // Number of related posts to display.
    'caller_get_posts'=>1
    );

    $my_query = new wp_query( $args );

    while( $my_query->have_posts() ) {
    $my_query->the_post();
    ?>

    <div class="relatedthumb">
        <a rel="external" href="<?php the_permalink()?>"><?php the_post_thumbnail(array(150,150)); ?><br />
        <?php the_title(); ?>
        </a>
    </div>

    <?php }
    }
    $post = $orig_post;
    wp_reset_query();
    ?>
</div>


/* 3 Some css style */
.relatedposts {width: 640px; margin: 0 0 20px 0; float: left; font-size: 12px;}
.relatedposts h3 {font-size: 20px; margin: 0 0 5px 0; }
.relatedthumb {margin: 0 1px 0 1px; float: left; }
.relatedthumb img {margin: 0 0 3px 0; padding: 0;}
.relatedthumb a {color :#333; text-decoration: none; display:block; padding: 4px; width: 150px;}
.relatedthumb a:hover {background-color: #ddd; color: #000;}
?>