How to reach down to these span's and concatenate their id's
<p>So I have:</p>

<pre><code>&lt;li id="foo"&gt;
   &lt;span&gt; bar &lt;/span&gt;
   &lt;ul&gt;
   &lt;li&gt;
      &lt;span id="1234"&gt;&lt;/span&gt;
   &lt;/li&gt;
   &lt;li&gt;
      &lt;span id="5678"&gt;&lt;/span&gt;
   &lt;/li&gt;

   &lt;/ul&gt;
&lt;/li&gt;
</code></pre>

<p>I need concatenate the span ids and make var foobar = "12345678"</p>

<p>P.S. I need start working from the top Li which has the id of "foo" since the span ids can be dynamic/unknown.</p>

<p>Thanks!</p>
