Sorry because this is probably lame but I've been trying to think this
one through for a few hours and after a few iterations can't figure
out the answer.  It's an exercise in the book "Learn to Program"
(Pragmatic)

Anyway, the problem is I want the program to loop and exit on the input 'BYE'
What's I've come up with is:

$stdout.sync = true (due to weird windows buffer stuff)

input = ''

while input != 'BYE'
    input = gets.chomp

  if input == input.upcase
    puts 'NO, NOT SINCE 1938!'
  elsif input == input.downcase
    puts 'HUH?! SPEAK UP, SONNY!'

end
end

What happens is it does exit on BYE but issues the elsif before
ending.  I've tried doing a
if input ==input.upcase !BYE , but was thrown an error.  I know UNTIL
exists but it hasn't been introduced in the book yet so want to work
with what I have.

tia
Stuart