<html>
<body>
Address:<br>
<textarea id="myTextarea">
342 Alvin Road
Ducksburg</textarea>
<p>Click the button to change the default value of the text area.</p>
<button type="button" onclick="myFunction()">Try it</button>
<script>
function myFunction() {
document.getElementById("myTextarea").defaultValue = "Fifth Avenue, New York City";
}
</script>
</body>
</html>