TomatoRAF 1.28.121006 Firewall Script

Hello all..
I´m having a problem to get the following Script working.
It seems not to work properly, but i am not sure.
May someone take a look at it? I put it at Scripts/Firewall.


#!/bin/sh
#######################
### Firewall Script ###
#######################
## get wan interface
WANIF=`nvram get wan_ifname`
WANMASK=`nvram get wan netmask`
## nat
### POSTROUTING
## Add route to access external modem over WAN-Port
#ip addr add 192.168.178.254/24 dev "$WANIF" brd +
iptables -t nat -A...

TomatoRAF 1.28.121006 Firewall Script