<DIV> like behavior for <IFRAME>

hi guys, i was wondering if you could help me with a small problem. i
need to have an <iframe> to behave like a <div>, in such a manner
that:

1) the <iframe> should have its own display space, indicated by the
"display: block;" style.
2) the <iframe> should resize automatically to display its contents.
3) the <iframe> should not have any border, or a small thin border if
necessary.

help in css or html is greatly appreciated. thanks!

o.j.