Wmode transparent

umm… I gotta question for all the jedis out there…
When you create a website, you optimize it for both IE and FF, right?
I was going to use transparent for my website, but I found out transparent doesn’t work with FF? Ouch!
I have frontpage (level1) -> when you press the enter button -> (level2) this is the main website. The size of the stage is about 770*580.
So how could I achieve the smooth background sync by using same jpeg in the
html (css) and under the stage? Just wondering, I thought this was a bit tricky. If you have any knowledge, please drop a line. Thank you.

I wasn’t sure where to put this message, if I posted in wrong section please move it. Gracias.