Lightweight native javascript drag'n'drop class
http://max201.github.io/doppe/
Just add script on your page:
<script type="text/javascript" src="doppe.js"></script>
<script type="text/javascript">
var d = new Doppe('#draggable', '.handler');
</script>
<div id="draggable">
<header class="handler">Drag</header>
<div class="body">
<h1>This element is draggable</h1>
</div>
</div>