What is wrong in this one?

#dialog --msgbox "Cleaning the current policy" 5 50
iptables -F
iptables -A FORWARD -j DROP
iptables -A INPUT -j DROP
iptables -A OUTPUT -j DROP

#INPUT
iptables -A INPUT -i eth0 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport 53 -j ACCEPT

#OUTPU
iptables -A OUTPUT -p tcp --dport 80 -j ACCEPT
iptables -A OUTPUT -m tcp -p tcp --dport 53 -j ACCEPT
iptables -A OUTPUT -m tcp -p tcp --dport 25 -j ACCEPT