cat and desc list

<?php
process_cat_trees();

function process_cat_trees( $cat='' ) {
/*****************************************************************
*
* alchymyth 2011
* transformationpowertools.com/wordpress
* a hierarchical list of all categories, with descriptions
*
******************************************************************/

   if($cat == '') :
//add any parameter for get_categories() into the code in the next line//
     foreach( get_categories('hide_empty=false') as $category ) :
     if( !$cat->parent ) { $next[] = $category; }
     endforeach;

   else:
     $next = get_categories('hide_empty=false&parent=' . $cat);
   endif;

 if( $next ) :
 foreach( $next as $cat ) :

 if(get_category($cat)->category_description) {
   $desc = get_category($cat)->category_description; }
  else { $desc = 'no description available'; }

 echo '<ul><li><a href="' . get_category_link($cat->term_id) . '"><strong>' . $cat->name . '</strong></a><span><p>' . $desc . '</p></span></li>'; echo "\n";
 process_cat_trees( $cat->term_id );
 endforeach;
 endif;

 echo '</ul>'; echo "\n";
}
?>