title: How to replace style class using mootools
body: <p>How to replace style class with mootools.Consider, </p>
  
  <pre><code>&lt;form&gt;
  &lt;div class="form-label"&gt;
      &lt;label&gt;User ID&lt;/label&gt;
  &lt;/div&gt;
  &lt;div class="form-element"&gt;
      &lt;input type="text"  name="userid"&gt;
  &lt;/div&gt;
  &lt;div class="form-label"&gt;
      &lt;label&gt;password&lt;/label&gt;
  &lt;/div&gt;
  &lt;div class="form-element"&gt;
      &lt;input type="text"  name="password"&gt;
  &lt;/div&gt;
   &lt;/form&gt;
  </code></pre>
  
  <p>Here, I would like to replace style class <code>form-label</code> with <code>form-label-new</code>.</p>
  
  <p>Thanks </p>