title: JQuery - get element through id and then through class selector
body: <p>I have something like this</p>
  
  <pre><code>&lt;div id="div1"&gt;
     &lt;span class="label"&gt;some text&lt;/span&gt;
  &lt;/div&gt;
  &lt;div id="div2"&gt;
     &lt;span class="label"&gt;some text&lt;/span&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I want to select a given span through id and then throu class. Something like <code>#div1.label</code> or <code>#div2.span</code> but this way doesn't work. How I can?</p>