NOWAIT exit from sqlplus when ORA-12545

Hi
(it's for: Windows NT/XP and Oracle 8.1.7.4)

--
J have a problem when J run test.bat such as :
   sqlplus infolig/edfinfo_at_POR1_SPARE @my_file.sql
   if %errorlevel% NEQ 0 echo KO: %ERRORLEVEL% else echo OK
%ERRORLEVEL%
--
When my POR1_SPARE server is not accessible/not connected the test.bat
is waiting with ORA-12545.
--------------------------------------------------------------------------------------------------------------------------------

D:\IL\BD_IL5\EvoPrisme\Upgrade>sqlplus infolig/edfinfo_at_POR1_SPARE
@my_file.sql

SQL*Plus: Release 8.1.7.0.0 - Production on Ve Aou 18 15:16:31 2006



(c) Copyright 2000 Oracle Corporation.  All rights reserved.


ERROR:
ORA-12545: Connexion impossible car l'h¶te ou l'objet cible n'existe
pas


Entrez le nom utilisateur :
--------------------------------------------------------------------------------------------------------------------------------
Would it be possible to avoid it and exit the sqlplus immediately (is
it any SqlNet parameter) ?

Thanks a lot

mso