Tryit Editor v2.9

Edit This Code:
<!DOCTYPE html>
<html>
<head>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.2/jquery.min.js"></script>
<script>
$(document).ready(function(){
    $("input").change(function(){
        alert("The text has been changed.");
    });
});
</script>
</head>
<body>

<input type="text">

<p>Write something in the input field, and then press enter or click outside the field.</p>

</body>
</html>