Detecting when an iframe gets or loses focus

Issue

What's the correct way of detecting when an iframe gets or loses focus (i.e. will or will not receive keyboard events)? The following is not working in Fx4:

var iframe = /* my iframe */;
iframe.addEventListener("focus", function() { /* never gets called */ }, false);

Solution

Turns out it's not really possible. I had to change the logic of my page to avoid the need of tracking if the iframe has focus.

Answered By - CAFxX