yii2 modal loading content but header modal can not see it -

i can not understand why not show modal can help?

modal

<?php  modal::begin([      'header' => '<h2>accedi</h2>',         'id' => 'modalsmall',      'size' => 'modal-sm',      //keeps closing modal esc key or clicking out of modal.      // user must click cancel or x close      'clientoptions' => ['backdrop' => 'static', 'keyboard' => true],      'footer' => 'fdd'  ]);    echo "<div id='modalcontent'></div>";    modal::end();  ?>

js

$(function() {         $('#modalbutton a').click(function(e) {         e.preventdefault();         $('#modalsmall').modal('show')           .find('.modal-content')           .load($(this).attr('href'));        });       });

what see

there not close button

<?php   modal::begin([         'header' => '',         'headeroptions' => ['id' => 'modalheader'],         'id' => 'modalsmall',         'size' => 'modal-medium', //medium          'clientoptions' => ['backdrop' => 'static', 'keyboard' => false]       ]);    echo "<div id='modalcontent'>         <div class='col-lg'>           <img src='".yii::$app->request->baseurl."/loading.gif' width='280' height='210' alt='loading...'> // put loading.gif in backend/web/ directory         </div>         </di>";  modal::end(); ?>  $(function() {        $('#modalbutton').click(function(e) {        e.preventdefault();        $('#modalsmall').modal('show')          .find('.modal-content')          .load($(this).attr('value')); document.getelementbyid('modalheader').innerhtml = '<button aria-hidden="true" data-dismiss="modal" class="close" type="button">×</button><h3>' + $(this).attr('title') + '</h3>';        });      }); 

how call?

use yii\helpers\url; <p>         <?= html::a(yii::t('app', 'add something'), null, ['class' => 'btn btn-success', 'id'=>'modalbutton',             'value'=>url::to(['/controller/action']),            'title'=>'show in modal header'            ])          ?>     </p>