title: knockout checked binding - only one checked
body: <p>I have a list of Admins with a check box. I want to be able to select only one Admin. </p>
  
  <p><strong>HTML:</strong></p>
  
  <pre><code>&lt;tbody data-bind="foreach: people"&gt;
  &lt;tr&gt;
   &lt;td&gt;
     &lt;input type="checkbox" data-bind="attr: { value: id }, checked: $root.selectedAdmin"&gt;
      &lt;span data-bind="text: name"/&gt;
  &lt;/td&gt;
  &lt;/tr&gt;
  &lt;/tbody
  </code></pre>
  
  <p><strong>JS:</strong></p>
  
  <pre><code>function Admin(id, name) {
      this.id = id;
      this.name = name;
  }
  
  var listOfAdmin = [
  new Admin(10, 'Wendy'),
  new Admin(20, 'Rishi'),
  new Admin(30, 'Christian')];
  
  var viewModel = {
      people: ko.observableArray(listOfAdmin),
      selectedAdmin: ko.observableArray()
  };
  
  ko.applyBindings(viewModel);
  </code></pre>
  
  <p>For Example if Admin id 10 is selected the other admins should be deselected.</p>
  
  <p>Is that Possible to do with Knockout? </p>