Why is mobile menu not working? -

background

i have website mobile hamburger-style menu, not working. menu button displaying correctly, nothing happens when clicked/touched.

code

backend php:

<!-- mobile links -->                     <a href="#" id="mobile-menu-icon" class="mobile-menu-icon show-for-custom-down" title="<?php esc_attr_e('mobile menu', 'punjaban' ); ?>"><span class="lines"></span></a>                     <a href="#" class="mobile-search-icon" title="<?php esc_attr_e('search', 'punjaban' ); ?>">                     </a>                      <!-- mobile menu -->                     <?php  register_nav_menus( array(     'mobile-primary-menu' => 'mobile navigation menu',     ) ); wp_nav_menu( array( 'theme_location' => 'primary', 'container_class' => 'mobile-primary-menu' ) ); ?> 

final html:

<!-- mobile links -->                     <a href="#" id="mobile-menu-icon" class="mobile-menu-icon show-for-custom-down" title="mobile menu"><span class="lines"></span></a>                     <a href="#" class="mobile-search-icon" title="search">                     </a>                      <!-- mobile menu -->                     <div class="mobile-primary-menu"><ul id="menu-primary-menu" class="menu"><li id="menu-item-21" class="search-icon menu-item menu-item-type-custom menu-item-object-custom menu-item-21"><a rel="nofollow" href="#">search</a></li> <li id="menu-item-407" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-407"><a rel="nofollow" href="/shop">shop</a></li> <li id="menu-item-239" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-239"><a rel="nofollow" href="/recipes">recipes</a></li> <li id="menu-item-17" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-17"><a rel="nofollow" href="/stockist">stockists</a></li> <li id="menu-item-598" class="fourth-child menu-item menu-item-type-post_type menu-item-object-page menu-item-598"><a rel="nofollow" href="http://www.punjaban.co.uk/our-story/">our story</a></li> <li id="menu-item-19" class="menu-item menu-item-type-custom menu-item-object-custom menu-item-19"><a rel="nofollow" href="/blog">blog</a></li> <li id="menu-item-300" class="menu-item menu-item-type-post_type menu-item-object-page menu-item-300"><a rel="nofollow" href="http://www.punjaban.co.uk/contact/">contact</a></li> </ul></div> 

can suggest might going wrong please?