Modifying function that generates the html for wp_list_pages help

In order to get the code for my navigation to work I am going to have to fix the way the html for wp_list_pages is outputted.

The code looks like:

<ul class="menu">
<li><a href="#nogo"><b><span>HOME</span></b><em></em></a></li>
<li><a href="#nogo"><b><span>ABOUT</span></b><em></em></a></li>
<li><a href="#nogo"><b><span>STUFF</span></b><em></em></a></li>
<li><a href="#nogo"><b><span>GALLERY</span></b><em></em></a></li>
<li><a href="#nogo"><b><span>DOMAIN</span></b><em></em></a></li>
<li><a href="#nogo"><b><span>EXIT</span></b><em></em></a></li>
</ul>

I see in post_template

function wp_list_pages($args = '') {
	if ( is_array($args) )
		$r = &$args;
	else
		parse_str($args, $r);

	$defaults = array('depth' => 0, 'show_date' => '', 'date_format' => get_option('date_format'),
		'child_of' => 0, 'exclude' => '', 'title_li' => __('Pages'), 'echo' => 1, 'authors' => '', 'sort_column' => 'menu_order, post_title');
	$r = array_merge($defaults, $r);

	$output = '';
	$current_page = 0;

	// sanitize, mostly to keep spaces out
	$r['exclude'] = preg_replace('[^0-9,]', '', $r['exclude']);

	// Allow plugins to filter an array of excluded pages
	$r['exclude'] = implode(',', apply_filters('wp_list_pages_excludes', explode(',', $r['exclude'])));

	// Query pages.
	$pages = get_pages($r);

	if ( !empty($pages) ) {
		if ( $r['title_li'] )
			$output .= '<li class="pagenav">' . $r['title_li'] . '
<ul>';

		global $wp_query;
		if ( is_page() )
			$current_page = $wp_query->get_queried_object_id();
		$output .= walk_page_tree($pages, $r['depth'], $current_page, $r);

		if ( $r['title_li'] )
			$output .= '</ul>
</li>
';
	}

	$output = apply_filters('wp_list_pages', $output);

	if ( $r['echo'] )
		echo $output;
	else
		return $output;
}

but since I don’t know PHP that well I don’t know how to configure it.

BTW Thanks to Stuart of CSSplay for his awesome navigation menu I am trying to implement.