Add a custom id in textarea
Each element should have only one ID and it should be unique. You can change the body texarea id with the hook_form_alter()

Example

/**
* Implements hook_form_alter().
*/
function YOURMODULE_form_alter(&amp;$form, &amp;$form_state, $form_id) {

  if (isset($form['#node']) &amp;&amp; $form['#node']-&gt;type == 'article') {
    // body textarea ID 
    $form['body']['und']['0']['#attributes']['id'] = 'redHat';
  }
}


but you cannot add the next one.