Detecting when an iframe gets or loses focus

Question

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:

Answer 1

Here is the code to Detecting when an iframe gets or loses focus

 // This code can be used to verify Iframe gets focus/loses.

      function CheckFocus(){

       if (document.activeElement.id == $(':focus').context.activeElement.id) {
                // here do something
            }
     else{
      //do something
    }
}