Any way to detect when screen/page is active window?

[Masgrada]

I've been trying to locate some code (hopefully java) to return when someone keeps a window open, but is not currently the active screen. I guess I wasn't sure what exactly to call it to search for it.

Anyone know? Is there even something like this?
thanks!

[Spudhead]

Could do with a little more info on what you need to do with it, but the window.onblur() (http://developer.mozilla.org/en/docs/DOM:window.onblur) event might do what you want.