Knockoutjs.com - Hello World Example

http://knockoutjs.com/examples/helloWorld.html

HTML

<script src="http://knockoutjs.com/downloads/knockout-2.2.1.js"></script>
<script src="http://cdnjs.cloudflare.com/ajax/libs/knockout.mapping/2.3.5/knockout.mapping.js"></script>
<div class='liveExample' >   
    <p>First name: <input data-bind='value: firstName' /></p> 
    <p>Last name: <input data-bind='value: lastName' /></p> 
</div>

CSS

body { font-family: arial; font-size: 14px; }
.liveExample { padding: 1em; background-color: #EEEEDD; border: 1px solid #CCC; max-width: 655px; }
.liveExample input { font-family: Arial; }
.liveExample b { font-weight: bold; }
.liveExample p { margin-top: 0.9em; margin-bottom: 0.9em; }
.liveExample select[multiple] { width: 100%; height: 8em; }
.liveExample h2 { margin-top: 0.4em; font-weight: bold; font-size: 1.2em; }

JavaScript

// Here's my data model
var ViewModel = function() {
    this.firstName = ko.observable('first');
    this.lastName = ko.observable('last');
};

var myVM = new ViewModel();

ko.applyBindings(myVM); // This makes Knockout get to work

myVM.lastName('maiden name'); // Test an update

var newData = {'firstName': 'new', 'lastName': 'person'};

// Try update the ViewModel
ko.mapping.fromJS(newData, myVM);

// Intended result - UI updates to 'new person'