xorg.conf help

I was told to go to xorg.conf to disable my touchpad, but firefox tells me that there's no such cite. Is it www.xorg.conf or am I missing something?
Thanks in advance!

Open your xorg.conf and look for the "InputDevice" section of your mouse. The actual "Device" will probably be "/dev/psaux" or "/dev/input/mice". Now change that to "/dev/input/mouseX where X is the number of the mouse you want to use (the mouse you plugged in).
You can find out with "cat /dev/inputX". Try them all out while moving your mouse until you find the right one. Then use that in your xorg.conf and restart X.