NAME
        UnLockRecord -- Unlock a record (V36)

   SYNOPSIS
        success = UnLockRecord(fh,offset,length)
        D0                     D1   D2     D3

        bool unlockrecord(bptr,ulong,ulong)

   FUNCTION
        This releases the specified lock on a file.  Note that you must use
        the same filehandle you used to lock the record, and offset and length
        must be the same values used to lock it.  Every lockrecord() call must
        be balanced with an UnLockRecord() call.

   INPUTS
        fh      - File handle of locked file
        offset  - Record start position
        length  - Length of record in bytes

   RESULT
        success - Success or failure.

   BUGS
        See lockrecord()

   SEE ALSO
        lockrecords(), lockrecord(), unlockrecords()