Iframe with auto highlight
ItzWarty is right: the parent page cannot link to the child document, even to find out its height. Back in 2008, Michael Mahemoff published a detailed review of Cross-Domain Communication with IFrames , which may provide you with some guidance.
Hopefully along the way, however, HTML5 includes an improvement to this situation called " Multiple Document Transfer ", which is supported in Firefox 3, Safari 4, Chrome 2, Opera 9.2 and even IE ... 8. If your users are using only supported browsers, you can use it.
Perhaps you could set the scroll attribute on the IFRAME element to the default “auto” and test window.postMessage - if it succeeds, set the scroll to “no” and use the function to evaluate the IFRAME accordingly.
I recently looked into a similar issue (parent page from domain.tld creating page at blog.domain.tld), but I was able to use the "old document.domain hack " described by Mahemoff, although it is not supported in Opera.
Good luck.
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