$category_id = null;

if ( $option == "com_content" ) {

  if ( $view == "category" ) {

   /* category list pages (blog or list style) */

   $category_id = (int)$id;

  } else if (array_key_exists("catid",$_REQUEST)) {

   /* if the category id is in the URL */

   $category_id = (int)JRequest::getInt("catid",0);

  }

  if ( $category_id === null && $view == "article" ) {

   /* if it's an article page without the catid mentioned in the url */

   $nullDate = $db->Quote($db->getNullDate());

   $my_id = $db->getEscaped((int)$id);

   $query = "SELECT  title,  id,  catid "

       . " FROM #__content WHERE id = '$my_id' AND state = 1"

       . " AND ( publish_up = " .  $nullDate

       . " OR publish_up <= CURRENT_TIMESTAMP )"

       . " AND ( publish_down = " . $nullDate

       . " OR publish_down >= CURRENT_TIMESTAMP  )";

   $db->setQuery( $query, 0, 1 );

   $row = $db->loadObject();

   $category_id = $row->catid;

  }

}

/* Now customise any of the following rules for your use.

 * $category_id will correspond to the category id of the

 * article being displayed (if one is being displayed!)

 */

if ($category_id == 460) return 1;/* on category 460, return module 1 */