I have the following structure:

...stuff ..
<input id="test-input" type="text" />
<iframe id="test-frame" src="whatever.php" />
.. more stuff ..
I need to change value of "test-input" from within that iframe. Typically I'd use
parent.document.getElementById('test-input').value = 'whatever';
but the problem is, iframe and document are on different domains, so I can't access parent.document

Is there some workaround for it? I have full access to both top and iframe document, so can add any javascript to both.