How do I create a "closed" Flex Accordian control?

I'm trying to create a navigation panel based on the Flex Accordion control. The 2 things I'm trying to figure out are how to:

1. modify the Accordion so that all of the of "panels" are closed by default. (normally one of the 开发者_如何学Gopanels is open by default)
2. treat some of the Accordian headers as just simple buttons (ie you click and an event is triggered instead of an accordion panel opening)

Does anyone have any pointers on implementing these 2 items or know of any existing components that could yield this behavior?

Thanks!

Flexlib has CanvasButtonAccordionHeader, which would help implement the button functionality.

This SO question suggests starting with flexlib's WindowShade component instead, which might make the "none-selected" case easier.