Transparent background possible?

I’m builiding a swf that will play on a web page. It’s a “build” where the page starts as blank and the animation “wipes” on in sections. The web page has a gradient background, and the swf will have a soft drop shadow.

Is there a way to give the swf a transparent background so we don’t have to try to “match” the gradient it will appear on top of?

If this isn’t clear I can post the swf or fla file.

Also, on this subject, what are the “Window” settings in the html publish settings? The options are Window, Transparent Windowless or Opaque Windowless. I’ve tried these in the past and they don’t seem to have any affect at all.

Thanks for help!