illegal group command

hello dear
i want to make immobile layers by entering the code in lammps.but it shows this error.i checked the error but it didnt help
can anybody help me
thanks

variable T equal 398
variable V equal vol
variable dt equal 1
variable p equal 200
variable s equal 10
variable d equal $p*$s

variable kB equal 1.3806504e-23 # [J/K] Boltzmann
variable kCal2J equal 4186.0/6.02214e23
variable A2m equal 1.0e-10
variable fs2s equal 1.0e-15
variable convert equal {kCal2J}*{kCal2J}/{fs2s}/{A2m}

dimension 3
units real
atom_style full
neighbor 2.0 bin

#neigh_modify delay 5
neigh_modify delay 0 every 1 check yes

#lattice fcc 0.8

#include system.in.init

read_data system2.data

#include system.in.settings

– Default styles (for solo “SPCE” water) –

group hydrogen type 2
#group water type 1 2
group cu type 3
group oxygen type 1
group bottom type 3
group top type 4

group 3 bottom region wall
region bottom block INF INF INF 0 3 0 3 0 4 unit box
group 4 top region wall
region upper block INF INF INF 0 3 0 3 0 4 unit box
create_atoms 3 region Cu

This is where the problem is:

group 3 bottom region wall
ERROR: Illegal group command (../group.cpp:367)

Maybe you meant to say:

group bottom region wall

As I said earlier, study this example *carefully*:

examples/friction/in.friction

Aidan

2015-11-16 4:09 GMT-07:00 Mehdi zarei <[email protected]...>: