wp: related post

realted-post.php

			<?php $orig_post = $post;
				global $post;

				$categories = get_the_category($post->ID);

				if($categories){

					$categori_id = array();

					foreach ($categories as $category) {
						$categori_id[] = $category->cat_ID;
					}

					$post_loop = new WP_Query(array(
						'posts_per_page' => 3,
						'category__in' => $categori_id,
						'post__not_in' => array($post->ID),
						'orderby' => 'rand'
					));

					if($post_loop->have_posts()){ ?>
						<h2 class="related_post_title">Suggested Articles For You:</h2>
						<div class="related-post-area">
							<ul>
								<?php while($post_loop->have_posts()){ ?>
									<?php $post_loop->the_post(); ?>
										<li>
											<a href="<?php the_permalink(); ?>"  class="thumbnail-image" ><?php the_post_thumbnail(); ?></a>
											<h1 class="thumbnail-text"><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></h1>
										</li>
							   <?php } ?>
							</ul>
						</div>
					
					<?php }

				}
				$post = $orig_post;
				wp_reset_query();

			 ?>