Floating Ads

[Freezerator]

Hi,

i want to implement floating ads to my forums, but i am breaking my head on how.
I have used this source code http://www.webmasters-central.com/t/floatingads.shtml

This works when i make a htm file, with no problems. But the biggest question is how do i integrate this into my forums?

I have posted the first two edits in my header, but where must i leave the 3th one?
If someone can help me with this, because i have tried several options, but i don't seem to get it right.

Thanks in advance.