Kendo UI Menu disabling Menu

Kendo UI Menu disabling Menu

HTML

<script src="http://cdn.kendostatic.com/2012.1.515/js/kendo.all.min.js"></script>
<link href="http://cdn.kendostatic.com/2012.1.515/styles/kendo.common.min.css" rel="stylesheet" /> 
<link href="http://cdn.kendostatic.com/2012.1.515/styles/kendo.blueopal.min.css" rel="stylesheet" /> 
<div id="menu"></div>
<button id='enable'>Enable</button>

CSS

html { font: 12px Arial, Helvetica, sans-serif; }

JavaScript

var menu = $("#menu").kendoMenu().data("kendoMenu");

$("div#menu").kendoMenu({
    dataSource:[{text:"Actions",value:1,items:[{text:"First",value:2},{text:"Second",value:2,menu:false}]}]
});

$("#enable").on('click',function(){
     menu.enable("li:last", false);
});