how to open another port using lokkit ?

[chas <panda skinnyhippo com>]

At the moment, I'm using lokkit to only allow ssh and http 
connections to my machine.  I have a custom application that
runs on port 3333 - how can I enable this with lokkit. 
So far, I'm doing this in Lokkit :

1. Select high security:

   [x] High Security  [ ] Medium Security  [ ] Low Security

2. Click on "Customize" and then allow incoming:
   
   [ ] DHCP           [x] SSH             [ ] Telnet
   [x] WWW(HTTP)      [ ] Mail(SMTP)      [ ] FTP


3. Other ports _____________________


What should I put in this last section ? 


Do I just add something like this to /etc/services : 
customapp    3333/tcp
customapp    3333/udp

Then run lokkit again and enter "customapp" in other ports ? 

Thank you in advance,

chas