Serial Port Programming in Java

[rfid]

Hi,
I am writing a program to read and write via serial port in Win Xp.
I am using Java Comm API. I downloaded SimpleRead.java from sun's site,
coompiled and ran it. I have a RFID reader attached to my PC via Serial
port. I am trying to read the data coming from the reader after it reads
the tag. when I run the SimpleRead.java, it just hangs up and does
nothing. Could anyone please tell me how to get the data from the tag?
I woul appreciate any kind of help!
Tahnk you