The comment list is not displayed in cakephp.

<?php

class Comment extensions AppModel {
    public$belongsTo='Post';
}

?>

<?php

class Post extensions AppModel {
    public$hasMany='Comment';

    public$validate=array(
        'title' = > array(
            'rule' = > 'notEmpty',
            'message' = > 'empty'
        ),
        US>'body'=>array(
            'rule' = > 'notEmpty'
        )
    );
}

?>

<h2><?phpechoh($post['Post']['title']);?>/h2>

<p><?phpechoh($post['Post']['body']);?>/p>

<h2>Comments<h2/>
<ul>
<?php foreach ($post['Comment'] as $comment): ?>
<li><?phpechoh($comment['body'])?>by<?phpechoh($comment['comment']);?></li>
<?php endforeach;?>
</ul>