fuel_FORMCLASS_search_form

<?php echo Form::open(
    array(
        'action' => '/search/',
        'method' => 'get',
        'id' => 'nav-bar-search',
        'class' => 'navbar-form navbar-left',
        'role' => 'search' )
     ); ?>
    <div class="form-group">
    <input type="text" class="form-control" placeholder="Search" name="q">
  </div>
  <button type="submit" class="btn btn-default">Submit</button>
<?php echo Form::csrf(); echo Form::close(); ?>