How to delegate from a Page Fragment to its parent?

Hi,

I would like to use a Page Fragment that contains the buttons [OK], [Cancel] and [Apply].
A click on the OK buttons invokes a call to the btnOK_action() in the Page Fragment's backing bean.
However, since the fragment is included in several pages, I would like to delegate to a btnOK_action() that resides in the backing bean of the parent page.

What is the best way to do this?

Thanks in advance, Stefan