how to display part of a menu tree?

Question

I'm trying to deal with Wordpress 3.0. It's rather cool thing but I can't get on with one problem. For example, I have such menu tree. Menu tree is constructed from pages.

Home
   news
   video
   audio
Blog
   About author
   Favourite colors
      red
      blue
      green
My car
   wheels
   tires

The Idea is: main menu consists of root elements: home, blog, my car On the left side I would like to display children elements of current active root element.

For exammple if person is on the "home" page, on the left part he should see:

  news
  video
  audio

If user is on the "Blog" page, he should see:

About author
       Favourite colors
          red
          blue
          green

I can't find an API to do that. Can you sugest me please where can I find it?

UPD: @Jason McCreary I've seen I've seen wp_list_pages() and tried it. I din't get how can I use it: Please, see my template for a page:

    <?php
/*
 Template Name: page_news

 * @package WordPress
 * @subpackage Twenty_Ten
 * @since Twenty Ten 1.0
 */

get_header(); ?>
<h1>page_news</h1>
<h1>Children menu:</h1>
<?php wp_list_pages('echo=0&child_of=8&title_li='); ?>
<div id="container">
        <div id="content" role="main">

        <?php
        /** Get category id by name*/
        //$catId = get_category_by_slug('news')->term_id;
        query_posts('category_name=news');
        get_template_part( 'loop', 'page' );
        ?>

        </div><!-- #content -->
</div><!-- #container -->

<?php get_sidebar(); ?>
<?php get_footer(); ?>

See this line of code:

<?php wp_list_pages('echo=0&child_of=8&title_li='); ?>

I do have the page with id=8 (I see it in URL). Page with id=8 has several children. I want to print them, but they are not printed. The output of the function wp_list_pages() is nothing. I don't know why... :(

Answer 1

Check out wp_list_pages(). It is useful for providing child navigation in the sidebar.