calling categories in a custom post type

Question

I'm creating a custom post type by adding the add_action( 'init', 'create_radiotalks' ); text to the functions.php page:

add_action( 'init', 'create_radiotalks' );

function create_radiotalks() {
    register_post_type( 'radiotalks',
        array(
            'labels' => array(
            'name' => __( 'Radio Talks' ),
            'singular_name' => __( 'Radio Talk' ),
            'add_new' => __( 'Add New' ),
            'add_new_item' => __( 'Add New Radio Talk' ),
            'edit' => __( 'Edit' ),
            'edit_item' => __( 'Edit Radio Talk' ),
            'new_item' => __( 'New Radio Talk' ),
            'view' => __( 'View Radio Talk' ),
            'view_item' => __( 'View Radio Talk' ),
            'search_items' => __( 'Search Radio Talks' ),
            'not_found' => __( 'No radio talks found' ),
            'not_found_in_trash' => __( 'No radio talks found in Trash' ),
            'parent' => __( 'Parent Radio Talk' ),
),
            'public' => true,
        )
    );
}

when entering the add new radio talk info, I would like to add the applicable categories and tags, but they do not show up in the admin side bar? How do I make the categories/tags available to my custom post type? thanks for your help.

-don

Answer 1

By adding the 'taxonomies' argument:

'public' => true,
'taxonomies' => array( 'category', 'post_tag' ),

Answer 2

or by register taxonomy:

<?php
register_taxonomy_for_object_type('category', 'radiotalks');
register_taxonomy_for_object_type('post_tag', 'radiotalks');