How to add Newsletter Widget below the content in Genesis Child Themes

functions.php

// Code to register a newsletter widget area

genesis_register_sidebar( array(
	'id'		=> 'newsletter',
	'name'		=> __( 'Newsletter', 'custom-theme' ),
	'description'	=> __( 'This is the newsletter section.', 'custom-theme' ),
) );
 
// Add the newsletter widget after the post content

add_action( 'genesis_after_post_content', 'custom_add_newsletter_box' );
function custom_add_newsletter_box() {
	if ( is_singular( 'post' ) )
	genesis_widget_area( 'newsletter', array(
		'before' => '<div id="newsletter">',
	) );
}