Getting Document Title From Iframe

I want to be able to get title of a document that is presented within an Iframe with the id "popupFrame". There may be more than 1 instance of the iframe in the page.

var elementCount = document.all("popupFrame").length;
for (var i = 0 ; i < elementCount ; i++)
{
alert("src = " + document.all("popupFrame",i).src);
alert("title = " + document.all("popupFrame",i).document.title);
}

But the wierd thing is that the title is always the title of the document that contains the Iframe. NOT the title of the document conatined within the Iframe. At least in IE7 which is all that I have tested it with so far.