Mobile Nav without Javascript

<div id="navigation" role="navigation">     
          <?php wp_nav_menu( array( 'container' => 'ul' ) );     ?> 
     </div>
<div id="mobilenav">
          <form class="mobilenav">
          <select name="themenu" onchange="location = this.options[this.selectedIndex].value;">
               <option value="" class="first">MENU</option>
               <?php $args = array(
                    'order'                  => 'ASC',
                    'orderby'                => 'menu_order',
                    'post_type'              => 'nav_menu_item',
                    'post_status'            => 'publish',
                    'output_key'             => 'menu_order',
                    'nopaging'               => true );
                    $items = wp_get_nav_menu_items( 'main-menu', $args );            
                    foreach ($items as $item) { 
                    echo '<option value="' .$item->url. '">' .$item->title. '</option>';
                    }
               ?> 
          </select>
          </form>
     </div>

/* mobilenav styling */

#mobilenav {text-align:center;}
form.mobilenav {margin:.3em;}
.mobilenav select { color:#444;padding:.5em;border:0;margin:.5em 0;text-align:center;border-radius:10px;-moz-border-radius:10px;}
.mobilenav select option {padding:.2em 1em;}

/* base CSS */
#navigation { display:none; }

/* desktop CSS */
#navigation { display:block;}
#mobilenav { display:none; }