Thematic Theme Custom Walker Adds description to Thematic Menu (#access/primary menu)

gistfile1.php

<?php
// updated working version, adds menu description in span tags
// reference: http://forums.themeshaper.com/topic/thematic-menus-demystified-1

class Custom_Walker extends Walker_Nav_Menu {
    function start_el(&$output, $item, $depth, $args) {
        global $wp_query;
        $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

        $class_names = $value = '';

        $classes = empty( $item->classes ) ? array() : (array) $item->classes;

        $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item ) );
        $class_names = ' class="' . esc_attr( $class_names ) . '"';

        $output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';

        $attributes  = ! empty( $item->attr_title ) ? ' title="'  . esc_attr( $item->attr_title ) .'"' : '';
        $attributes .= ! empty( $item->target )     ? ' target="' . esc_attr( $item->target     ) .'"' : '';
        $attributes .= ! empty( $item->xfn )        ? ' rel="'    . esc_attr( $item->xfn        ) .'"' : '';
        $attributes .= ! empty( $item->url )        ? ' href="'   . esc_attr( $item->url        ) .'"' : '';

        $item_output = $args->before;
        $item_output .= '<a'. $attributes .'>';
        $item_output .= $args->link_before . apply_filters( 'the_title', $item->title, $item->ID ) . $args->link_after;
        $item_output .= ' <span>' . $item->description . '</span>';
        $item_output .= '</a>';
        $item_output .= $args->after;

        $output .= apply_filters( 'walker_nav_menu_start_el', $item_output, $item, $depth, $args );
    }
}
      
function childtheme_nav_menu_args() {
    $walker = new Custom_Walker;
    $args = array (
        'theme_location'    => 'primary-menu',
        'menu'              => '',
        'container'         => 'div',
        'container_class'   => 'menu',
        'menu_class'        => 'sf-menu',
        'fallback_cb'       => 'wp_page_menu',
        'before'            => '',
        'after'             => '',
        'link_before'       => '',
        'link_after'        => '',
        'depth'             => 0,
        'walker'            => $walker,
        'echo'              => false
    ); 
    return $args;
}
add_filter('thematic_nav_menu_args', 'childtheme_nav_menu_args');

Thank you!

thanks