FindNext procedure

  DECLARATION:  FindNext(var S : SearchRec)

      PURPOSE:  Returns next disk entry after a call to FindFirst

         UNIT:  The DOS unit

      REMARKS:  S must be the same one passed to FindFirst.

                NOTES:  Errors are reported through DosError.
                        Only possible error is 18 - (No More Files).

      EXAMPLE: See FindFirst.