I'm not sure what you are asking. The flash background, is entirely different than the HTML doc background.
From your description you are calling the image from the html. If you want the background image to "fill" the background then you need to do one of a couple things:
Make the background image the same size as the html file width and height, or use css to call and control the image then use the repeat attribute to fill the background with multiple "tiled" instances of the image in its original size.
I apologize for the confusion. Yes I want to call the image from html. So I need to make the image the same size as
my broswer window. Also I want the image to look like one whole image.
If your calling the background image from the html than you have a couple options, again, one would be to use an image the same size as the html doc size, if it is a non-tiling image, like a landscape or something, than that is the best way to go, or make the html size the same as the image size, otherwise if the image is not that size, you would probably want to use a seamless tiling image, a smaller image that is designed to tile seamlessly without being able to see edges of each image. You have some other options if you have a decent graphics prog and a suitable image:
Great! I will try it out.
Thanks for your help.