Flash 5...changing the background

I have been working w/ flash 5 and I have created a small animation that requires the background to be black. Is there something I put put in the code of the html document that will change the background color? I have created 16 layers( one for eachanimation) and I have tried to make an extra layer for the background. It always wants to overwrite the other animations even after I have selected the option fill in or color in behind. Please help! Thanks.

Daniel