Script that gets the first tag of post and query all other posts with the same tag

Question

The script gets the first tag of a post and retrieves in a wordpress loop all other posts with the same tag. I can't seem to get it working:( Any ideeas?

$posttags = get_the_tags();
$count=0;
if ($posttags) {
  foreach($posttags as $tag) {
    $count++;
    if (1 == $count) {
      $tag = $tag->name . ' ';
    }
  }
}
query_posts('tag='.$tag.''&'showposts=-1'); 
    while (have_posts()) : the_post(); ?>

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

<? endwhile; 
wp_reset_query(); 

Take care

Answer 1

the query expects the tag slug, not the tag name:

$tag = $tag->slug . ' ';

and there is an error in the query syntax; corrected:

query_posts('tag='.$tag.'&posts_per_page=-1');

edit: full code rearranged:

$posttags = get_the_tags(); 
if ($posttags) {   
    foreach($posttags as $tag) {     
        $tag = $tag->slug;  break;  
    } 
query_posts('tag='.$tag.'&posts_per_page=-1');      
    while (have_posts()) : the_post(); ?> 

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

    <?php endwhile;  
    wp_reset_query();  
}