How to add category option to a

Hi,

How to add category option to a custom page?
I am using the plugin advent calendar.
Plugin author has given this piece of code to give his custom page the possibility to entry text. But it gives no possibility to add a category to this post.

function acal_change_post_type_params( $custom_post_type_params ) {
$custom_post_type_params['supports'] = array(
'title',
'editor',
'thumbnail'
);
return $custom_post_type_params;
}
add_filter( 'pvb_acal_cpt_params', 'acal_change_post_type_params' );

How can I get it done?

Thanks!!