<html>
<head>
<script>
function changeTarget()
{
document.getElementById('w3s').target="_blank";
}
</script>
</head>
<body>
<a id="w3s" href="/">Visit ZiQiangXueTang</a>
<br><br>
<input type="button" onclick="changeTarget()" value="Change target">
<p>Try the link before and after you have pressed the button!</p>
</body>
</html>