title: How do I theme Form API buttons in Drupal?
body: <p>The default output from Drupal's Form API is:</p>
  
  <pre><code>&lt;input id="edit-submit" class="form-submit" type="submit" value="Save" name="op"/&gt;
  </code></pre>
  
  <p>How do I theme that so I get:</p>
  
  <pre><code>&lt;button id="edit-submit" class="form-submit" type="submit"&gt;
    &lt;span&gt;Save&lt;/span&gt;
  &lt;/button&gt;
  </code></pre>
  
  <p>I need the inner span-tag so I can use the sliding doors CSS technique.</p>
  
  <p>I guess I need to override theme_button($element) from form.inc but my attempts so far have been unsuccessful.</p>