<div id="main">
<div id="main">
<div id="div1">Keep this div</div>
<div>1</div>
<div>2</div>
<div>3</div>
<p>4</p>
<a href="">Keep this hyperlink</a>
</div>
<button id="button">Clear</button>
<script class="cssdeck" src="//cdnjs.cloudflare.com/ajax/libs/jquery/1.8.0/jquery.min.js"></script>
$('#button').on('click', function () {
$('#button').on('click', function () {
$('#div1').nextAll(':not(a)').remove();
});