[support] PHP: block visibility by term

[crozilla]

All,
 
I kinda know what I'm doing in Drupal, but this trick has baffled me. 
This is what I want to have happen:  When the page has the term 221, 
block/24 is visible, when the page doesn't have the term, the block is 
disabled. Sounds simple, right?

Here is code I found on Drupal that seemed to do what I wanted, but 
didn't work for some reason. I don't really know PHP that well, and was 
hoping someone could point out the problem.

------------------
|
<?php
  //code snippet for causing block to show based on a node's taxonomy term.
  $make_block_visible = FALSE;
  $term_id_to_trigger_show_block = 221;

  if ((arg(0) == 'node') && is_numeric(arg(1))) {
    $terms = taxonomy_node_get_terms(arg(1));
    foreach($terms as $term) {
      if ($term->tid == $term_id_to_trigger_show_block) {
         $make_block_visible = TRUE;
      }
    }
  }
?>

------------

|Also, is this possible using a CCK text field, instead of a category 
term? That would be ideal.

Thanks,

Peter