js check if div have another div

<script>
    window.onload = function() {
        var parentDiv = document.getElementById("commentBox");
        var childDiv = document.getElementById("comment1");
        if (parentDiv.contains(childDiv)) {
            alert("yes");
        } else {
            alert("no");
        }
    }
</script>
<div class="row leftpad collapse" id="commentBox">
    <div id="comment1">
        <div class="col-md-3 dir-rat-left"> <i class="fa fa-user-circle" aria-hidden="true"></i>
            <h6>James </h6>
        </div>
        <div class="col-md-9 dir-rat-right">
            <p class="removemarg">always available, always helpfull that goes the same for his team that work with him - definatley our first phone call.</p>
        </div>
    </div>
</div>