OLD()

  Short:
  ------
  OLD()  On Line Documentation - TOPIC oriented help system

  Returns:
  --------
  NIL

  Syntax:
  -------
  OLD()

  Description:
  ------------
  This is ON LINE DOCUMENTATION , similiar to NG or Windows help.
  There are no parameters, but it has a couple of additional
  exported functions that allow TOPIC selection and DEVELOPMENT

  The documentation is stored in a DBF database, with one
  record per TOPIC. A TOPIC has a TITLE, stored in the TOPIC field,
  a variable length TEXT entry (can be as long as needed) stored in the
  TEXT field, and hotlinks stored in the KEYS field, which link the TOPIC
  to other topics via a (S)ee also button.

  The options available to the user are:

    (C)ontents   -- go to the CONTENTS screen, a sort of index or
                    table of contents to the topics in the database
    (S)ee also   -- select from related topics
    (O)ther      -- not yet used
    (B)ack       -- go to previous screen

  The DBF structure is TOPIC C 35
                       KEYS  M
                       TEXT  M

  Additional Exported Functions:

  OLD_DEV(bDevelopMent)
      Where bDevelopment is a proc called during development
      of the doc system. Always pass {||OLD_MOD()} to enable
      development, and NIL to disable development. When development
      is active, a prompt called (M)odify appears at the bottom
      of the screen, allowing CREATION, EDITING, DELETING and
      LINKING of topics.

      The options avaialable to the developer are:

       Add Topic                 - create a new TOPIC record
       Edit Topic                - edit the current TOPIC record
       Delete Topic              - delete the current TOPIC record
       Modify SEEALSOs           - add/delete See Also references
       Generate CONTENTS record  - generate the CONTENTS record
                                   either by tagging selected TOPICS
                                   or using ALL topics

  OLD_TOPIC(cTopic)
      This sets the current TOPIC for OLD(). For instance, on
      entry into QUERY(), you could call OLD_TOPIC("QUERY BY EXAMPLE").
      Presuming you had a TOPIC defined called "QUERY BY EXAMPLE",
      this is what would come up when OLD() was called or activated
      with a hotkey.

      Call OLD_TOPIC("") to clear the topic. The default topic is
      the CONTENTS page.

  Examples:
  ---------
  For development:
       OLD_DEV({||OLD_MOD()})
       OLD()
  For distribution, simply comment out the OLD_DEV() call.

  For hotkey activation:
      SETKEY(K_WHATEVER,{||OLD()}  )

  When in a particular part of the program:
       OLD_TOPIC("TOPIC NAME...")
  to activate a particulat topic.

  Notes:
  -------
  There's no reason this couldn't be used alongside of the
  traditional Clipper context sensitive 'field level' help.

  Source:
  -------
  S_OLD.PRG