<nav id="site-navigation" class="navigation main-navigation" role="navigation">
<button class="menu-toggle"><?php _e( 'Menu', 'twentythirteen' ); ?></button>
<a class="screen-reader-text skip-link" href="#content" title="<?php esc_attr_e( 'Skip to content', 'twentythirteen' ); ?>"><?php _e( 'Skip to content', 'twentythirteen' ); ?></a>
- <?php wp_nav_menu( array( 'theme_location' => 'primary', 'menu_class' => 'nav-menu' ) ); ?>
+ <?php wp_nav_menu( array( 'theme_location' => 'primary', 'menu_class' => 'nav-menu', 'menu_id' => 'primary-menu' ) ); ?>
<?php get_search_form(); ?>
</nav><!-- #site-navigation -->
</div><!-- #navbar -->