<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<script>
function CopyToClipboard(element) {
var doc = document
, text = doc.getElementById(element)
, range, selection;
if (doc.body.createTextRange)
{
range = doc.body.createTextRange();
range.moveToElementText(text);
range.select();
}
else if (window.getSelection)
{
selection = window.getSelection();
range = doc.createRange();
range.selectNodeContents(text);
selection.removeAllRanges();
selection.addRange(range);
}
document.execCommand('copy');
window.getSelection().removeAllRanges();
document.getElementById("btn").value="Copied";
}
</script>
<style>
i {font-size: 50px}
</style>
</head>
<body>
<div id="text">
<i>Hello</i> world!
</div>
<input id="btn" onclick="CopyToClipboard('text')" type="button" value="Copy"></input>
</body>
</html>