select all html elements based on rel value
<p>I have some html elements in my code like this</p>

<pre><code>&lt;div rel="test1"&gt;item1&lt;/div&gt;
&lt;div rel="test1"&gt;item2&lt;/div&gt;
&lt;div rel="test1"&gt;item3&lt;/div&gt;
&lt;div rel="test2"&gt;item4&lt;/div&gt;
&lt;div rel="test2"&gt;item5&lt;/div&gt;
</code></pre>

<p>and I need a way to select all the divs that use <code>rel="test1"</code> and add a class to them
how can I do this with <code>jQuery</code>?</p>
