title: JQuery UI icon not showing in span
body: <p>I have a span where I want to display a jQuery UI icon ( .ui-icon-plusthick ). This is the code:</p>
  
  <pre><code>&lt;div&gt;
       &lt;div id="pop"&gt;
            &lt;label for="ptitle"&gt;Plot title: &lt;/label&gt;
            &lt;textarea class="nrtextarea" id="ptitle" maxlength="80" /&gt;
            &lt;span class="ui-icon-plusthick" title="Add"&gt;&lt;/span&gt;
       &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>Via CSS I tried setting:</p>
  
  <pre><code>display: inline-block;
  width: 20px;
  height: 20px;
  </code></pre>
  
  <p>But with no result; moreover width and height remain 0px x 16px. What am I doing wrong?</p>
  
  <p>Thanks</p>