<html>
<body>
<p id="demo">Click the button to make a header.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var h=document.createElement("H1");
var t=document.createTextNode("Hello World");
h.appendChild(t);
document.body.appendChild(h);
};
</script>
</body>
</html>