<!DOCTYPE html>
<html>
<body>

<ul id="myList1"><li>Coffee</li><li>Tea</li></ul>
<ul id="myList2"><li>Water</li><li>Milk</li></ul>

<p>Click the button to copy an item from one list to another.</p>

<button onclick="myFunction()">Try it</button>

<p>Try changing the <em>deep</em> parameter to false, and only an empty LI element will be cloned.</p>

<script>
function myFunction() {
    var itm = document.getElementById("myList2").lastChild;
    var cln = itm.cloneNode(true);
    document.getElementById("myList1").appendChild(cln);
}
</script>

</body>
</html>