I understand that you're attempting to access serial ports through Swing - but this is actually two (or more) separate processes - one is to access the serial port and send/receive some data; the second is to display this data in a Swing GUI. Which part are you having problems with, and what exactly is going wrong? Are you getting any exceptions?
The code does download, compile, and run - but it seems to just be a generic "add two numbers in a Swing form" example (built through Netbeans) mashed together with some javax.comm serial port stuff. Does the "add two numbers" stuff have anything to do with your problem? (If not, why post it?) I'm not sure what I'm supposed to do with the GUI or what results I'm supposed to see.
Write once, run anywhere, because there's nowhere to hide! - /. A.C.