First, you need to follow the link provided by newinlinux and download the driver. Then, follow the instructions provided on the website to install it.
Last, but not least, follow these instrustions by Grogan
The instructions are for XFree86 and you're running X11R6 from X.org but the only difference will be the command to call the program. The article calls for xf86config but you'll need to use xorgconfig. Everything else will be the same.