Add more Listenning port to Apache Http Server for Ubuntu

I have to tell you that this is my method. I'm not sure is there any better workaround to handle this. I'm on Ubuntu Intrepid Ibex.

First, I add this 2 lines to /etc/apache2/ports.conf (I'm gonna add listenning port at port 8000)

NameVirtualHost *:8000
Listen 8000

Second, Edit file named /etc/apache2/site-enabled/000-default by following step

copy content of all in and paste text next to the old one and change *:80 of the new one to *:8000

So you have something similar to this ......

Last, restart your apache with this command "/etc/init.d/apache2 restart"

Booom! Your Apache Http Server will now can listen to 8000 port.

Failed memo :
1. can't restart apache with this command apache2 -k restart
2. If adding just Listen 8000 in /etc/apache2/ports.conf, the 8000 port query is listenned but no thing is displayed.