Sending variable to page from iFrame?

I’m trying to make a cross domain iframe and want the iframe to dynamic resize the height. I have read that this is not possible, but if I own both domains I thought that I in my cross domian could make an variable which tells the height of the page and then send it via the iFrame to my page.

My crossdomain page has a javasacript like this:

var pageHeight = document.getElementById("container").clientHeight;

And my page would get the page like this:

<iframe src="" width="100%" height="The height from my crossdomain" frameborder="0" scrolling="no">

Can I send the pageHeight to my page?

Thanks in advance…

From what I read, if it’s cross-domain you can’t send variables through iframe. The browser just see 2 domains.