How do I refer to an <iframe>'s document using jQuery to get its height()?

Question

I'm trying to get the height of an <iframe>d document. My first instincts were:

$('iframe').document.height();

or

$('iframe').contentWindow.document.height();

Those don't work, and I'm not having much luck searching. I would appreciate any help!

Answer 1

$("iframe",top.document).contents().height();
alert("iframe height=" + $("iframe",top.document).height());