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// Add custom code to Genesis primary navigation extras
// @link http://www.rfmeier.net/add-a-custom-primary-nav-extras-within-genesis/
add_filter( 'wp_nav_menu_items', 'custom_nav_item', 10, 2 );
function custom_nav_item( $menu, stdClass $args ){
        
        // make sure we are in the primary menu
        if ( 'primary' != $args->theme_location )
        	return $menu;
        
        // see if a nav extra was already specified with Theme options
        if( genesis_get_option( 'nav_extras' ) )
                return $menu;
        
        // additional checks?
        
        // append your custom code
        $menu .= sprintf( '<li class="right">%s</li>', __( 'Call Today! (908) 441-2659' ) );
        
        // return the menu
        return $menu;
        
}