Windows/Linux/Mac Eclipse plugin to compile and upload arduino sketches

Hello,

The problem
I want to use a method in order to display debug information on the Eclipse monitor.
But the Serial.begin(9600); method is underlined in red.

My system

Mac OS 10.8.4

Arduino IDE 1.0.5

Eclipse IDE for C/C++ Developers
Version: Juno Service Release 2
Build id: 20130225-0426

(as all files have been downloaded and installed last week-end, I suppose my versions are up to date)

My research

But as I just want to have this common line working:

void setup()
{
serial.begin(9600);
}

the serial.begin method is underlined in red and therefore, compilation fails (Symbol ‘serial’ could not be resolved).

My Question
How can I proceed to send debug data onto the Eclipse monitor?

Thanks for the (long) time you spent on this forum…