How to setup USB Scroll Mouse in Linux

This is my experience in setting up my mouse (USB, scroll mouse) in my new Slackware Linux box. On standard installation, Slack installer did a good job of detecting my USB mouse but did not properly configure it for the scroll wheel. So, I just couldn't use the wheel to scroll down. On my Mandrake system, it did detect my USB mouse and the configured the scroll wheel automagically. This is what I need to add in my /etc/X11/xorg.conf in inputdevice section:

option "Protocol" "IMPS/2"

option "ZAxisMapping" "4 5"
option "Buttons" "5"

Make sure the Protocol is IMPS/2 because protocol PS/2 does not support scroll wheel. Happy scrolling!...