Kendo UI TabStrip selection

HTML

<link href="http://cdn.kendostatic.com/2011.3.1129/styles/kendo.common.min.css" rel="stylesheet"/>
<link href="http://cdn.kendostatic.com/2011.3.1129/styles/kendo.default.min.css" rel="stylesheet"/>
<script src="http://code.jquery.com/jquery-1.7.1.min.js"></script>        
<script src="http://cdn.kendostatic.com/2011.3.1129/js/kendo.all.min.js"></script>
<div id="tabstrip"> 
    <ul>
        <li>Tabb</li>
    </ul>
    <div></div>
</div>

JavaScript

var tabstrip = $("#tabstrip").kendoTabStrip({collapsible: true}).data("kendoTabStrip");

tabstrip.append({ text: "test", contentUrl: "/echo/json/" });