Show child categories of current category page

Hi,

I want to display child categories of current category in category page. I have a code

<?php
    if (is_category()) {
    $this_category = get_category($cat);
    }
    ?>
    <?php
    if($this_category->category_parent)
    $this_category = wp_list_categories('orderby=id&show_count=0
    &title_li=&use_desc_for_title=1&child_of='.$this_category->category_parent.
    "&echo=0"); else
    $this_category = wp_list_categories('orderby=id&depth=1&show_count=0
    &title_li=&use_desc_for_title=1&child_of='.$this_category->cat_ID.
    "&echo=0");
    if ($this_category) { ?> 

<ul>
<?php echo $this_category; ?>

</ul>
<?php } ?>

I think it works perfect for default post categories. But i want to use it in custom post type categories. How to do that?

register_taxonomy(__('recipe-category'),'recipe',array(
			'hierarchical' => true,
			'labels' => $labels,
			'with_front' => false,
			'rewrite' => array(
                        'slug' => 'receptai'
                         ),

I hope you understand me ??