Editing the html that is published from flash to add a background image

[gdesigner36]

I am trying to edit the html that is published from flash. I am using the new i.e click to activate resolve update publish setting that macromedia has developed.So it results in a different code structure. I want to add a background image that will take up a user entire web browser window, as the web site does not. In dreamweaver this is easy just a page properties. How would i go about doing it in flash so I dont have to use dreamweaver at all?
Any help would be great

Thanks