kendoAutoComplete clear

HTML

<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.2.710/styles/kendo.common.min.css">
<link rel="stylesheet" href="http://cdn.kendostatic.com/2012.2.710/styles/kendo.default.min.css">
<script src="http://cdn.kendostatic.com/2012.2.913/js/kendo.all.min.js"></script>
<div id="content">

    <span>First name :</span>
    <input id="getPersonListByFirstName" 
       data-role="autocomplete" 
       data-text-field="FirstName"
       data-bind="source: datas, value: nom" />
<br/>
<br/>
    <span>Last name :</span>
    <input id="getPersonListByLastName" 
           data-role="autocomplete" 
           data-text-field="LastName"
           data-bind="source: datas, value: nom" />
 
    
    <br/>
    <span data-bind="text: nom.FirstName"></span>
    <br/>
    <span data-bind="text: nom.LastName"></span>
    
</div>

<input id="reset" type="button" value="initialize">

JavaScript

var listPerson = [{
    "Id": 13896,
    "FirstName": "Mathieu",
    "LastName": "Beland",
    "Description": "Mathieu Beland"},
{
    "Id": 13897,
    "FirstName": "Michel",
    "LastName": "Brisebois",
    "Description": "Michel Brisebois"},
{
    "Id": 13898,
    "FirstName": "Tristan",
    "LastName": "Dube",
    "Description": "Tristan Dube"},
{
    "Id": 13899,
    "FirstName": "ROBERT M.",
    "LastName": "GRANATSTEIN",
    "Description": "ROBERT M. GRANATSTEIN"},
{
    "Id": 13900,
    "FirstName": "JEFFREY R.",
    "LastName": "LLOYD",
    "Description": "JEFFREY R. LLOYD"},
{
    "Id": 13901,
    "FirstName": "GIBSON",
    "LastName": "BROCK",
    "Description": "GIBSON BROCK"},
{
    "Id": 13902,
    "FirstName": "ROBERT",
    "LastName": "GRANATSTEIN",
    "Description": "ROBERT GRANATSTEIN"},
{
    "Id": 13903,
    "FirstName": "CASSELS & GRAYDON LLP",
    "LastName": "BLAKE",
    "Description": "CASSELS & GRAYDON LLP BLAKE"}];

var viewModel = kendo.observable({
    datas: listPerson,
    nom: null
});

kendo.bind($('#content'), viewModel);

$("#reset").click(function() {
    viewModel.set("nom", viewModel.datas[1]);
});