class Fixnum

# File script/txt2html, line 21
def ordinal
  # teens
  return 'th' if (10..19).include?(self % 100)
  # others
  case self % 10
  when 1 then return 'st'
  when 2 then return 'nd'
  when 3 then return 'rd'
  else    return 'th'
  end
end