IS Methods

<!DOCTYPE html>
<html>
<body>

<p>Click the buttons to compare the <strong>first item</strong> in two of the lists.</p>

<button onclick="myFunction('myList1','myList2')">Compare List 1 and 2</button>
<button onclick="myFunction('myList1','myList3')">Compare List 1 and 3</button>
<br><br>

List 1:
<ul id="myList1"><li>Water</li><li>Milk</li></ul>
List 2:
<ul id="myList2"><li>Coffee</li><li>Tea</li></ul>
List 3:
<ul id="myList3"><li>Water</li><li>Fire</li></ul>

<p><strong>Note:</strong> Internet Explorer 8 and earlier does not support the isEqualNode method.</p>

<p id="demo"></p>

<script>
function myFunction(x,y) {
  var item1 = document.getElementById(x).firstChild;
  var item2 = document.getElementById(y).firstChild;
  var x = item1.isEqualNode(item2);
  document.getElementById("demo").innerHTML = x;
}
</script>

</body>
</html>