def check(username, password)
  username =~ /[^a-z]/ && password == File.read(directory+username)
rescue Errno::ENOENT
  return false
end

show_user "the friggn message" unless check(username, password)

## old one
def a(x, y, z)
    raise "Oops" unless x < 3 and y > 7 and z < x*y
    x*y*z
end