Problemas com model bootstrap

<div class="cupons">
    <div class="container">
      <h1>Cupons</h1>
        <div class="row">
        
             <?php
                $args = array('post_type'=>'cupons', 'showposts'=>-1);
                $my_cupons = get_posts( $args );
                $count = 0; if($my_cupons) : foreach($my_cupons as $post) : setup_postdata ($post) ;
              ?>

                <div class="col-md-3 col-lg-3">
                <div class="cupons-box">
                
                    <p> <?php the_title(); ?> </p>

                    <?php the_post_thumbnail(false, array('class' => 'img-responsive')); ?>

                    <!-- Small modal -->
                    <button type="button" class="btn btn-danger btn-custom center-block" data-toggle="modal" data-target=".bs-example-modal-sm">Gerar cupom</button>
                    <div class="modal fade bs-example-modal-sm" tabindex="-1" role="dialog" aria-labelledby="mySmallModalLabel">
                      <div class="modal-dialog modal-sm" role="document">
                        <div class="modal-content">
                          
                          <div class="modal-header">
                                <button type="button" class="close" data-dismiss="modal" aria-label="Close"><span aria-hidden="true">×</span></button>
                                <h4 class="modal-title" id="myModalLabel"><?php echo rwmb_meta('titulo'); ?></h4>
                            </div>
                          <div class="modal-body">
                                <p>Acesso o site <a href="<?php echo rwmb_meta('url'); ?>">clicando aqui!</a></p>
                                <div class="input-group">
                                    <span class="input-group-addon" id="basic-addon3">Código:</span>
                                    <input type="text" class="form-control" id="basic-url" aria-describedby="basic-addon3" value="<?php echo rwmb_meta('codigo-cupom'); ?>">
                                </div>
                          </div>
                          <div class="modal-footer">
                            <button type="button" class="btn btn-default center-block" data-dismiss="modal">Fechar</button>
                          </div>

                        </div>
                      </div>
                    </div>
                </div> 
                
            </div>

               <?php
                endforeach;
                endif;
              ?> 

              <div class="clearfix"></div>
        </div>
    </div>
</div>