Knockoutjs.com - Control types example

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

HTML

<div class='liveExample'>    
        <h3>Radio View model</h3>
        <table>
        <tr>
            <td class="label">Radio buttons:</td>
            <td>
                <label><input name="Test" type="radio" data-bind="checked: radioSelectedOptionValue, checkedValue: true" />Alpha</label>
                <label><input name="Test" type="radio" data-bind="checked: radioSelectedOptionValue, checkedValue: false" />Beta</label>
            </td>
        </tr>
    </table>  
    <span data-bind="text: radioSelectedOptionValue"></span>
</div>

JavaScript

var viewModel = function() {
    this.radioSelectedOptionValue = ko.observable(false);     
};
ko.applyBindings(new viewModel());