<!DOCTYPE html>
<html lang="en-US">
<head>
<style>
div{
padding: 10px;
margin-bottom: 10px;
border-style: dotted;
border-bottom-width: 1px;
}
</style>
</head>
<body>
<h1>CSS border-bottom-width Property</h1>
<div>
This is div container.
</div>
<button onclick="myFunction()">Click Me</button>
<script>
var x = document.getElementsByTagName("div")[0];
function myFunction(){
x.style.borderBottomWidth = "5px";
}
</script>
<p><strong>Note</strong>: Click on the button to change the 'border-bottom-width' from 1px to 5px.</p> </body>
</html>