How to post processor can plot the displacement sum

HI!
The below is my comm file for linear static problem,
It runs okay only has a problem that I can't plot displacement sum
at the post processing. It just show x, y, z displacements not their summation.
Can you teach how to correct the comm file?
thanks

..................................

DEBUT();

MA=DEFI_MATERIAU(ELAS=_F(E=189000000000.0,
NU=0.3,),);

MAIL=LIRE_MAILLAGE(FORMAT='MED',);

MAIL=MODI_MAILLAGE(reuse =MAIL,
MAILLAGE=MAIL,
ORIE_PEAU_3D=_F(GROUP_MA='Force_BC',),);

MODE=AFFE_MODELE(MAILLAGE=MAIL,
AFFE=_F(TOUT='OUI',
PHENOMENE='MECANIQUE',
MODELISATION='3D',),);

MATE=AFFE_MATERIAU(MAILLAGE=MAIL,
AFFE=_F(TOUT='OUI',
MATER=MA,),);

CHAR=AFFE_CHAR_MECA(MODELE=MODE,
DDL_IMPO=_F(GROUP_MA='Fix_BC',
DX=0.0,
DY=0.0,
DZ=0.0,),
FORCE_FACE=_F(GROUP_MA='Force_BC',
FX=3.9723e6,),);

RESU=MECA_STATIQUE(MODELE=MODE,
CHAM_MATER=MATE,
EXCIT=_F(CHARGE=CHAR,),);

RESU=CALC_ELEM(reuse =RESU,
MODELE=MODE,
CHAM_MATER=MATE,
RESULTAT=RESU,
OPTION=('SIGM_ELNO_DEPL','EQUI_ELNO_SIGM',),
EXCIT=_F(CHARGE=CHAR,),);

RESU=CALC_NO(reuse =RESU,
RESULTAT=RESU,
OPTION=('SIGM_NOEU_DEPL','EQUI_NOEU_SIGM',),);

IMPR_RESU(FORMAT='MED',
UNITE=80,
RESU=_F(MAILLAGE=MAIL,
RESULTAT=RESU,
NOM_CHAM=('SIGM_NOEU_DEPL','EQUI_NOEU_SIGM','DEPL',),),);

FIN();

if post processing in Salome you simply choose 'modulus' for your deformed shape and scalar plot