<!DOCTYPE html>
<html>
<body>
<p>Click the button to find out if the specified namespace is default.</p>
<button onclick="myFunction()">Try it</button>
<p><strong>Note:</strong> Internet Explorer 8 and earlier does not support the isDefaultNamespace method.</p>
<p id="demo"></p>
<script>
function myFunction() {
var d = document.documentElement;
var x = d.isDefaultNamespace("http://www.w3.org/1999/xhtml");
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>