For use in communicating between two iframes, I was using:

top.document.frames['someFrame'].getElementById('someID').style.width = '100px';

However, perhaps because the iframe is being written using document.write ... FF isn't having it.

I've since switched to:

top.document.getElementById('someFrame').document.getElementById('someID').style.width = '100px';

While I was able to use this same targeting to set the iframe's 'src' attribute, targeting things within the document of said iframe is proving difficult. The technique doesn't work in any of my browsers.

Where am I going wrong?