<!DOCTYPE html>
<html>
<head>
<style>
#myDIV {
width: 100px;
height: 100px;
background-color: coral;
color: white;
}
</style>
</head>
<body>
<p>Click the "Try it" button to change the width of the DIV element:</p>
<button onclick="myFunction()">Try it</button>
<div id="myDIV">
<h1>myDIV</h1>
</div>
<script>
function myFunction() {
document.getElementById("myDIV").style.width = "500px";
}
</script>
</body>
</html>