Attempt to APPEND BLANK with optional retry
──────────────────────────────────────────────────────────────────────────────

 Syntax

        GT_AddRec( nSeconds )

 Arguments:

      nSeconds - Number of retry attempts (one per second)

 Returns:

      .T. is successful, .F. otherwise

 Description:

      Attempts to perform an APPEND BLANK to a network table.  If successful,
      returns .F., with the blank record selected.  If unsuccessful, waits
      for one second and tries again until nSeconds attempts have been made.

      If nSeconds is 0, the routine will loop indefinately.

      The table to be added to should be SELECTed before calling.

 Examples:

      Add a record, aborting if not successful at the first attempt :

          GT_AddRec( 1 )

 Source: ADDREC.PRG

 Author:  Martin Colloby