title: if else condition with Knockout
body: <p>I'm very new at Knockout.
  I have a problem, how can I use if/else with Knockout.</p>
  
  <p>For example like this</p>
  
  <pre><code>&lt;ul class="list-group" data-bind="foreach: users"&gt;
      &lt;li class="list-group-item" data-bind="click : setasUser"&gt;
          &lt;i class="fa fa-circle text-success"&gt;&lt;/i&gt; &lt;span data-bind="text: name"&gt;&lt;/span&gt;
      &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>I want to have a non-clikable item if <code>username == x</code></p>
  
  <p>How can I do this?</p>