title: AutoHiding Custom Scrollbar Flex 4
body: <p>I have a custom scrollbar that controls a group as its viewport.</p>
  
  <pre><code>&lt;s:HGroup&gt;
          &lt;s:Group width="520" height="380" clipAndEnableScrolling="true" id="descriptionBox" &gt;
              &lt;s:RichText  text="Test Test Test Test Test Test Test "
                          width="490" textAlign="justify" fontFamily="Arial" fontSize="12" color="#999999" /&gt;
          &lt;/s:Group&gt;
          &lt;s:VScrollBar viewport="{descriptionBox}" 
                  left="{descriptionBox.x + descriptionBox.width + 10}" 
                  top="10" 
                  height="{descriptionBox.height}"
                  fixedThumbSize="true"
                  skinClass="VScrollBarSkin"/&gt;
      &lt;/s:HGroup&gt; 
  </code></pre>
  
  <p>I want to make that scrollbar autohide when the contents of that group is not larger than the view, any idea how to do that generically (meaning that I dont want to depend on a component inside the viewport group)? </p>
  
  <p>Thanks.</p>