I tried that as well. Still Edit is not working

<script type="text/javascript" src="../../jquery-1.8.0.min.js"></script>
<script type="text/javascript" src="../../jquery.easyui.min.js"></script>
<script>
$('#tt').treegrid({
url:'data.json',
idField:'Dashboard',
treeField:'Dashboard',
columns:[[
{title:'Dashboard',field:'Dashboard',width:60},
{field:'URL',title:'URL',width:200}
]]
});
function editNode(){
var node = $('#tt').treegrid('getSelected');
if (node){
alert(node.id);
$('#tt').treegrid('beginEdit',node.Dashboard);
}
}
</script>
</head>
<body>
<h2>TreeGrid</h2>
<div style="margin:10px 0;">
<a href="#" onclick="remove()">Remove</a>
<a href="#" onclick="append()">Append</a>
<a href="#" onclick="editNode()">Edit</a>
<a href="#" onclick="getSelected()">GetSelected</a>
</div>
<table id="tt" class="easyui-treegrid" style="width:600px;height:400px"
data-options="url:'data.json',idField:'Dashboard',treeField:'Dashboard'">
<thead>
<tr>
<th data-options="field:'Dashboard',width:180">Task Name</th>
<th data-options="field:'URL',width:60,align:'right'">Persons</th>
</tr>
</thead>
</table>