Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<title>Page Title</title>

<script>
function myFunction() {
    document.getElementById("demo").innerHTML = "Hello JavaScript!";
}
</script>

<body>

<h1>My Web Page</h1>

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

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

</body>
</html>