KnockoutJs中的嵌套foreach不起作用

Question

我正在做的一切正确，但由于一些奇怪的原因，我无法嵌套列表显示

    <div>
     <span>Account</span>
    <hr/>
    <table>
    <thead>
        <tr>
            <th>System Name</th>
            <th>Manual link</th>
            <th>Contact No</th>
        </tr>
    </thead>
    <tbody data-bind="foreach: mapping.employee">
        <tr>
            <td data-bind="text :SystemName"></td>
            <td data-bind="text : ManualLink"></td>
            <td data-bind="text : ContactNo "></td>
        </tr>
        <tr>
            <table>
                <thead>
                <tr>
                    <th>AccountName</th>
                    <th>AccountType</th>
                    <th>Username</th>
                    <th>Password</th>
                </tr>
                </thead>
                <tbody data-bind="foreach: UserAccount">
                <tr>
                    <td data-bind="text: AccountName"></td>
                    <td data-bind="text: AccountType"></td>
                    <td data-bind="text: Username"></td>
                    <td data-bind="text: UserAccount"></td>
                </tr>
                </tbody>
            </table>
        </tr>
    </tbody>
</table>
<hr/>
</div>



    var data ={ "employee": [{
    "SiteId": 9,
    "SystemId": 1,
    "SystemName": "Glocus",
    "ManualLink": "http://www.Glocus.com/Guide",
    "ContactNo": "301-489-8989",
    "UserAccount": [{
        "AccountId": 1,
        "AccountName": "Sisij",
        "AccountType": "Customer System",
        "Username": "Tybeke",
        "Password": "*****"
       }, {
       "AccountId": 2,
         "AccountName": "gabid",
        "AccountType": "System System",
        "Username": "Tybeke",
        "Password": "*****"
    }]
    }, {
    "SiteId": "1",
      "SystemId": 2,
    "SystemName": "TheSecondWorld",
    "ManualLink": "http://www.TheSecondWorld.com/Guideplan",
    "ContactNo": "301-489-8989",
    "UserAccount": [{
                "AccountId": 1,
                "AccountName": "Uniqex",
                "AccountType": "Customer System",
                "Username": "TUniqux",
                "Password": "*****"
                 }, {
                "AccountId": 5,
                     "AccountName": "Celind",
                    "AccountType": "System System",
                    "Username": "GCElinds",
                    "Password": "*****"`enter code here`
                }]
    }]};

    model = function()
    {
    self = this;
    self.mapping = ko.mapping.fromJS(data);  
    };

ko.applyBindings（模型）;

http://jsfiddle.net/32765/2/

我已经有一段时间了。缺什么？任何帮助将不胜感激。我已经包含了上面提琴手的链接。