[horde] Horde_Form_Action_conditional_enable

[Liebe Markus (AE/BA-S) *]

Hi,

I am trying to find information on the usage of Horde_Form_Action_conditional_enable. I want to enable or disable an element on a form based on the value of another element.
As I did not find an example on this (I had a look at /hordedoc/developer/* and the various Horde Applications as well as the api) I wanted to ask, if anyone of you can point me to somwhere where I can find more information on how to use Horde_Form_Action_conditional_enable. Is there a Horde application that uses this class?

Markus