title: Dropdown Box with expanding optgroup
body: <p>Im looking for a select box that i can use that has expandible optgroups</p>
  
  <p>The options in the groups should not display until the mouse is move over the optgroup label</p>
  
  <pre><code>&lt;select&gt;
   &lt;optgroup label="group 1"&gt; 
    &lt;option&gt;1&lt;/option&gt; &lt;!-- Options within this group hidden until mouseover its group label --&gt;
    &lt;option&gt;2&lt;/option&gt;
    &lt;option&gt;3&lt;/option&gt;
    &lt;option&gt;4&lt;/option&gt; 
   &lt;/optgroup&gt;
   &lt;optgroup label="group 2"&gt;
    &lt;option&gt;1&lt;/option&gt; &lt;!-- Options within this group hidden until mouseover its group label --&gt;
    &lt;option&gt;2&lt;/option&gt;
    &lt;option&gt;3&lt;/option&gt;
    &lt;option&gt;4&lt;/option&gt;
   &lt;/optgroup&gt;
   &lt;optgroup label="group 3"&gt;
    &lt;option&gt;1&lt;/option&gt; &lt;!-- Options within this group hidden until mouseover its group label --&gt;
    &lt;option&gt;2&lt;/option&gt;
    &lt;option&gt;3&lt;/option&gt;
    &lt;option&gt;4&lt;/option&gt;
   &lt;/optgroup&gt;
  &lt;/select&gt;
  </code></pre>
  
  <p>I want to be able to do this becuase am going to have some very large options and it will help break them down. </p>
  
  <p>If i am unable to do this through an HTML select box + JS i would like to build a customised dropdown that will support this using DIV tags. If anyone knows where i can find any information about this or a tutorial that would be great.</p>
  
  <p>Thanks</p>