Error Placement / Styles

Is it possible to determine where the error class gets added?

 

for example:

 

<fieldset>
 <ul>
  <li><?php echo $form->input('User.password', array('label' => 'Password:')); ?>
          <p class="form_hint"><span class="bold red">Required:</span> Password must be minimum of 8 characters.</p></li>
  <li><?php echo $form->input('User.username', array('label' => 'Select a Username:')); ?>
          <p class="form_hint"><span class="bold red">Required:</span> Username can never be changed.</p></li>

 

 </ul>
</fieldset>

 

So if a field fails i would like to add the error class to the <li> so the entire row gets the error class like <li class="error">   

 

Thanks 

 

Dave