Twitter Bootstrap 2.3.2

HTML

<script src="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://netdna.bootstrapcdn.com/twitter-bootstrap/2.3.2/css/bootstrap-combined.min.css">
<body>
    <br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br /><br />
    <a id="popover-example" class="btn max-width-popover" href="#" data-placement="right" data-title="Popover title" data-content="Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content Popover content" >
        Popover
    </a>
</body>

CSS

.max-width-popover + .popover {
    max-width: 300px;
    max-height: 300px;
    overflow-y: auto;
}

JavaScript

$(function () {
    $('#popover-example').popover()
});