Iframe width problem in IE and Opera

Hi folks

I have a strange problem - in IE6 and Opera, in an iframe within a page which has left padding (or margin - it makes no difference) for the content, leaving room for a left hand menu:

the iframe is set to width: 100%. In FF, it takes this as 100% of the div it is in, as intended. But IE takes it as 100% of the screen width, and therefore puts some of the iframe off screen to the right:
http://ied.gospelcom.net/churchdesign-exampletest.php

I find it ever harder to understand because in other very similar situations I do have 100% iframes sitting happily within a div of less than full screen width.

Anyone know what is going wrong here? Or the proper way to do it?

Grateful thanks.

Tony

frames? what are those? j/k - they're not used much anymore. They'll be dropped entirely from future specs (if they ever come about). Look into includes.