jQuery: add css to parent
<p>I have the following HTML:</p>

<pre><code>&lt;div class="control-group"&gt;
            &lt;input value="" id="email" name="email" type="text" placeholder="E-mail"/&gt; &lt;span class="help-inline"&gt;&lt;/span&gt;
          &lt;/div&gt;
</code></pre>

<p>And the follow jQuery:</p>

<pre><code>var input = $(this);

$.getJSON("/email", { email: data }, function(json){
                if(json.valid == true){
                    input.parent().addClass("success");
                }
            });
</code></pre>

<p>How can I add the class 'success' to the div control-group? Also, how can I add content to the help-inline span?</p>

<p>Thanks.</p>
