problem after changing hostname

[sudeep_meh]

Hello I wanted to change the hostname in my macbook, so i followed the following advice i found on apple support given by one of the user:
>>>>>>>>>>>
Edit /etc/hostconfig.

Add the following line:
HOSTNAME=$HOSTNAME

where $HOSTNAME is the hostname you want to set.
That change will take effect after a reboot.

If you want the hostname to show up at the prompt,
add a line similar to the following one to your
.bash_profile:
PS1='\h:\w \u\$ '

where \h is the hostname, \w is the working directory
of the current user and \u is the name of the current
user.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
After i did that things have gone wrong. I made the changes and booted the computer.This is what i am getting now:
localhost:/root# CSRHIDTransitionDriver::stop
IOBluetoothHCIController::start Idle Timer Stopped.
Now i dont know what to do, i booted the system from the cd, went to terminal and thought of changing the hostconfig file, again (back to original), however, there is no vi or any editor available.
What can i do now? Please guide. I will appreciate a quick response as i whole of my research work is in my laptop