SWF on top of another SWF... controlling which is the higher Z Index

Hi, I am in a situation where I have two SWF files (two flash objects) on one HTML site, and they overlap just slightly, one has a background, and one is transparent with images and stuff in it (the one with the background is used for other purposes), it seems like the one with the background is overriding the other, I have tried in HTML to set them to different layers with the transparent one having a higher Z Index, then the one with the background…, how can I make it so that the transparent one is able to sit above the opaque one? Any help would be appreciated, thanks