Expanding children question

Hi there,

Not sure if this is the module I need and I'd like some advice.

I have a menu 2 levels deep, I want the menu to always show only the 1st level unless you are in the pages of the 1st level, in that case I'd like the menu to show the 2nd level sub-menu options.

I'll try to put an example.

I've got the widgets menu with the round widget and square widget sub-menu

- Widgets
-- Round widgets
-- Square widgets

So in the front page (or any other that is not the widgets page) the menu should only show "Widgets"

- Widgets

However if I go to the Widgets page (or the round or square pages), the menu should show the children too.

- Widgets
-- Round widgets
-- Square widgets

¿Do you know what I mean?

¿Can I configure this module to do that? if not ¿do you know of any module to accomplish that?

Thanks for your help
Manuel