# File lib/sup/modes/edit-message-mode.rb, line 418
  def edit_field field
    case field
    when "Subject"
      text = BufferManager.ask :subject, "Subject: ", @header[field]
       if text
         @header[field] = parse_header field, text
         update
       end
    else
      default = case field
        when *MULTI_HEADERS
          @header[field] ||= []
          @header[field].join(", ")
        else
          @header[field]
        end

      contacts = BufferManager.ask_for_contacts :people, "#{field}: ", default
      if contacts
        text = contacts.map { |s| s.full_address }.join(", ")
        @header[field] = parse_header field, text
        update
      end
    end
  end