system.io.port

Hi all
Please excuse me , i didn't find the proper place for discussing this question.
I want to use SYSTEM.IO.PORT class to access Serial port so
i searched the web and came across to the following MSDN Page:

system.io.port

But if you check this page you will find the Example secction without any example at all !!!? as it claims , there is a chat sample in which two user can start chat over serial port so it can be a good start point for me, BUT there is no sample code or download link there!!!

beside this if you know good resource or example for working with this CLASS please let me know.

Thanks in advance.
Regards.