Tryit Editor v2.9

Edit This Code:

<!DOCTYPE html>
<html>
<head>
<script>
function myFunction() {
    document.getElementById("demo").innerHTML = "You selected some text";
}
</script>
</head>
<body>

Some text: <input type="text" value="Hello world!" onselect="myFunction()">

<p id="demo"></p>

</body>
</html>