You haven't made it clear what you want to do. You are playing a
continuous warning. Then you decide you want to play something else.
So what do you want to do? You can't play two things at the same time.
You can:
a) Stop the first one and play the second.
b) Let the first one continue and not play the second.
c) Stop the first one, play the second and then resume the first.
(Actually, you'd have to start the first one over again; there's no
"pause".)
Good luck.
Kurt