<!DOCTYPE html>
<html>
<body>
Name: <input type="text" id="myText" value="Mickey">
<p>Click the button to change the value of the text field.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
document.getElementById("myText").value = "Johnny Bravo";
}
</script>
</body>
</html>