When browsing in Opera, occasionally a new window opens instead of a new tab, or in Word if I have two documents open at the same time, they are open in two different windows. Is there an easy keyboard shortcut to use that switches between the two windows? On a PC, I think it was ALT+TAB. I know that I can 4-finger swipe on the trackpad, but I'd prefer to be able to do it without moving from the keyboard. Thanks.