title: Drawing rectangles with Jquery
body: <p>I have a div called #llens where I need to draw some boxes ( div's). I can't understand why is not drawing. I'm a litle newbie so please be patient if I'm make a great mistakes :P</p>
  
  <p>that's the div :</p>
  
  <pre><code>  &lt;div id="estructura" class="collapse "&gt;
      &lt;section data-toggle="buttons-radio" class="btn-group btn-group-vertical"&gt;
          &lt;header id="professor" class="btn btn-primary boto_funcio "&gt;
               &lt;h2&gt;Professors&lt;/h2&gt; 
          &lt;/header&gt;
          &lt;header id="alumne" class="btn btn-primary boto_funcio "&gt;
               &lt;h2&gt;Alumnes   &lt;/h2&gt; 
          &lt;/header&gt;
          &lt;header id="text" class="btn btn-primary boto_funcio "&gt;
               &lt;h2&gt;Text      &lt;/h2&gt; 
          &lt;/header&gt;
      &lt;/section&gt;
  &lt;/div&gt;
  &lt;section class="span9"&gt;
      &lt;div id="llens"&gt;&lt;/div&gt;
      &lt;!-- llens --&gt;
  &lt;/section&gt; 
  </code></pre>
  
  <p><strong>Here is the example :</strong> <a href="http://jsfiddle.net/blackersoul/PLWkS/" rel="nofollow">http://jsfiddle.net/blackersoul/PLWkS/</a></p>
  
  <p>I 've done a fork from  the code there : <a href="http://jsfiddle.net/lollero/kDmqw/" rel="nofollow">http://jsfiddle.net/lollero/kDmqw/</a>  </p>