Reduce the secondary navigation menu to one level depth
<?php
//* Do NOT include the opening php tag shown above. Copy the code shown below.
//* Reduce the secondary navigation menu to one level depth
add_filter( 'wp_nav_menu_args', 'ns_secondary_menu_args' );
function ns_secondary_menu_args( $args ){
if( 'secondary' != $args['theme_location'] )
return $args;
$args['depth'] = 1;
return $args;
}
<!-- From No Sidebar Pro's functions.php -->