book this wordpress script for me personally, it's not working. I wish to obtain the first tag from the publish and query other posts who have a similar tag. TY!

<? // Start related posts by tag 
$posttags = get_the_tags();
$count=0;
if ($posttags) {
  foreach($posttags as $tag) {
    $count++;
    if (1 == $count) {
      $tag = $tag->slug . ' ';
    }
  }
}

query_posts('tag='.$tag.'&posts_per_page=-1');
    while (have_posts()) : the_post(); ?>

    <p><a href="<?php the_permalink(); ?>"><?php the_title(); ?></a></p>

<? endwhile; 
wp_reset_query(); ?>

Unsure concerning the relaxation from the logic of the code only one problem is always that you're utilizing the same $tag variable to loop with the $posttags in addition to store the first tag value. Rather than doing something so complex, why don't you only use the very first value inside your $posttags array.

Something similar to this -

<? // Start related posts by tag 
$posttags = get_the_tags();
if ($posttags) {
    query_posts('tag='.$posttags[0].'&posts_per_page=-1');
    //rest of your code here