I have a problem: people who spell "voila" any other way than "voila".
The only exception? If you happen to spell it "voilà" with the accent.
Please. You have to stop. No more "wala" "walla" or "wah-la"
Because you're killing America with bad spelling.
If you spell "voila" as "viola" I will giggle a little, because I used to play the viola. However, it's hard to imagine you finishing some cool project and yelling "VIOLA!" (although it is a lovely instrument with a beautiful timbre, so I kind of feel you on that one.)