title: bootstrap: error text input without control group
body: <p>Apparently, the only way to generate a highlighted red text field in Bootstrap 2.3.2 is to create a div with the class <code>control-group</code> and <code>error</code> around it (see: <a href="https://stackoverflow.com/questions/14361517/mark-error-in-form-using-bootstrap">Mark error in form using Bootstrap</a>).</p>
  
  <p>Isn't there any single Bootstrap class I can assign to the input field to make it red? The documentation only offer the other "solution". Rather, I'd prefer to transform something like this:</p>
  
  <pre><code>&lt;div class="control-group error"&gt;
    &lt;div class="controls"&gt;
      &lt;input type="text" id="inputError"&gt;
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>into something like this, much easier to animate or/and maintain:</p>
  
  <pre><code>&lt;input type="text" class="someBootstrapErrorClass"&gt;
  </code></pre>
  
  <p>Is it possible?</p>