Bootstrap and datepicker

HTML

<script src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.1.0/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.1.0/css/bootstrap.min.css">
<link rel="stylesheet" href="http://eternicode.github.io/bootstrap-datepicker/bootstrap-datepicker/css/datepicker.css">
<script src="http://eternicode.github.io/bootstrap-datepicker/bootstrap-datepicker/js/bootstrap-datepicker.js"></script>
<input class="datepicker">

JavaScript

$('.datepicker').datepicker({
    startDate: "auto",
    todayHighlight: true
}).on('changeDate', function() {
    alert($(this).val());
});