# File lib/rmail/header.rb, line 112
    def [](name_or_index)
      if name_or_index.kind_of? Fixnum
        temp = @fields[name_or_index]
        temp = temp.value unless temp.nil?
      else
        name = Field.name_canonicalize(name_or_index)
        result = detect { |n, v|
          if n.downcase == name then true else false end
        }
        if result.nil? then nil else result[1] end
      end
    end