Help: serial portname

Please help me, help me.

I have an Diecimila Board- usb. I am using one pushbutton and I want to see the graphic in processing. I went to this site:
http://webzone.k3.mah.se/projects/arduino-workshop/projects/arduino_meets_processing/instructions/pushbutton.html

and everything is working fine on my arduino board.
In processing, I changed the portname to
String portname = "/dev/tty.usbserial-A4001mmw";
which is what i am using in arduino...

but there is this error : gnu.io.PortInUseException: Unknown Application
at gnu.io.CommPortIdentifier.open(CommPortIdentifier.java:
354) What is it? please help! ::
:-[ :-[ :-[ :-[
Thanks. Alisha

You can only open the port once. If you want to open it in processing, make sure the serial monitor is closed in the arduino IDE.

You might also need to run the macosx_setup.command. See the Processing serial library page for more troubleshooting suggestions: Serial / Libraries / Processing.org

Thanks a lot for your help!... Well, it's still not working at all... no idea why. The serial monitor in arduino was closed.. Well, I will look at the Processing's link right now. Best-Alisha

Thanks a Lot.

IT IS WORKING! YOUPPI! the answer was on the processing's Link.
the macosx_setup.command.

Many thanks.

Alisha