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

Question

I can not understand why I do not show well the modal can you help?
Modal
<?php
Modal::begin([
'header' => '<h2>Accedi</h2>',
'id' => 'modalSmall',
'size' => 'modal-sm',
//keeps from closing modal with esc key or by clicking out of the modal.
// user must click cancel or X to 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 I see
there is not the close button

Answer 1

<?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 to 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>