Make dropdown menu parent active?

Hi,

Is it possible to make the dropdown menu parent active while on one of the child pages in the menu?

I’ve tried quite a lot of stuff (changing classes, adding classes, etc.) but had no luck. Has anyone managed to get this to work?

Taken from the bootstrap guide to illustrate what I mean:

<li class="dropdown">
 <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-haspopup="true" aria-expanded="false">Dropdown <span class="caret"></span></a>
  <ul class="dropdown-menu">
 <li><a href="#">Action</a></li>
<li><a href="#">Another action</a></li>
<li><a href="#">Something else here</a></li>
</ul>
</li>

I want the ‘Dropdown’ menu item to be active while for example, on the Action page.

Thanks