Varying Opacity for a background?

[Corin]

Ok, I have searched all over and I cannot find anything about the code to make the background transparent for a page. I know it is somewhere because I used it once, but I can't remember it! Does anyone have any idea what I am talking about?

[Corin]

Oooh. Ok. I guess that will help my search a bit eh? Thanks!

[Corin]

No need to feel bad! I didn't mean to make you feel that way. Thanks for the link! I am reading up on it now. I am lost, but that just comes with the territory I guess. hehe.
Thanks again! =)

[Corin]

Well, everything that I see about a filter has to do with an image. I am just wanting the background for page to be more transparent. It is actually in an iframe. I guess technically it is on a part of an image, but not the whole thing. Here is the image I am wanting to use. (http://www.belikethat.org/junk/main2.jpg)
Then the iframe goes where the box is. Pretty obvious I know ;)