Getting output into Mathematica?

I've checked out the following link and had little success with this so far. I want to see the output of an arduino function in mathematica. How exactly do I do that? I believe I have the Serial IO downloaded and installed in the correct place.

Here is what I've followed thus far. I'm stuck trying to get my value "F" out of the Arduino.
http://playground.arduino.cc/Interfacing/Mathematica

Thanks.

ETA: It says "access to 'COM5' denied" That's the com port I've got the Arduino hooked up to and I have the ARduino IDE closed.