Hi, everyone: As we know, one can lock a door of a room, and people cannot enter, but a person can open if he/she was inside the room before the door is locked. And there's another locking method, in which after the door is locked, both the people inside and ouside of the room cannot open the door, unless the key is used. My question is what's the commonest way to express the second situation. For example. I was (...), and cannot go out, people outside cannot enter either, because they all have no key. Best wishes.