custom menus in wordpress

register:
 
<?php
register_nav_menus( array(
	'primary' => __( 'Primary Navigation', 'primarynav' ),
	'secondary' => __( 'Secondary Navigation', 'secondarynav' ),
	'footer' => __( 'Footer Navigation', 'footernav' ),
) );
 
?>
 
 
display:
 
<?php wp_nav_menu(array( 'theme_location' => 'footer')); ?>