<html>
<body>
<h1>My First JavaScript</h1>
<p id="demo">
JavaScript can react to events. Like the click of a button.
</p>
<script>
function myFunction()
{
document.getElementById("demo").innerHTML="Hello JavaScript!";
}
</script>
<button type="button" onclick="myFunction()">Click Me!</button>
</body>
</html>