How can I tell what the active element is?

[Csaba2000]

I feel like I'm missing something or asking the wrong question, but I didn't spot this in my reference books or
google:

How do I determine the active element on a web page (and whether there is one?)? I am only concerned about IE 5.5+.
And what about if the active element is located within a document (of a different domain) contained within an
I/Frame?

Thanks,
Csaba Gabor from New York.

PS. I have an off topic telephone forwarding question - is there a recommended newsgroup? I didn't see an obvious
one.