ie7 iframe clear bg?

is there a way to get an iframe to have trans background in ie7? normally unless you add a bg to one it is trans and shows through to watever is behind it, but in ie its white, i even tried to use css on the body tag to make the bg trans and it had no effect, .

I don't have copy of IE 7 to hand to test, but if you add the attribute

allowtransparency="true"

to your iframe element and then in the page that is displayed in the iframe use the CSS

body { background: transparent; }

it works in IE 6.