How to change the hostname in linux

Hi, I am trying to change the host name of a linux machine. I have modified /etc/hosts as follows :

/etc/nsswitch.conf is modified as follows : #hosts: db files nisplus nis dns ##hosts: files nisplus dns hosts: files

/etc/sysconfig/network ##HOSTNAME= HOSTNAME=

Then I have executed these on the shell : hostname

service xinetd restart

After executing these steps, my machine is not taking the new hostname. If I execute #hostname

I get hostname as (none)

Can anyone tell me what is that which I am missing here. Thanks in Advance!