Receiving SMS using GSM SIM900

I am trying to receive SMS using Arduino. But when i try to receive sms using the example code given in Arduino IDE I get an error saying “G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp: In member function ‘int GSM3SoftSerial::begin(long int)’:
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:180: error: ‘RXPIN’ was not declared in this scope
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:180: error: ‘PCICR’ was not declared in this scope
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:183: error: ‘PCMSK2’ was not declared in this scope
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:183: error: ‘PCMSK0’ was not declared in this scope
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:183: error: ‘PCMSK1’ was not declared in this scope
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp: In member function ‘void GSM3SoftSerial::setTX()’:
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:276: error: ‘TXPIN’ was not declared in this scope
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp: In member function ‘void GSM3SoftSerial::setRX()’:
G:\arduino-1.0.5-r2\libraries\GSM\GSM3SoftSerial.cpp:286: error: ‘RXPIN’ was not declared in this scope”

How do I proceed?

ReceiveSMS.ino (1.86 KB)

When I compile the RecceiveSMS.ino example for the Uno, I only get one "error"

Binary sketch size: 14,948 bytes (of a 32,256 byte maximum)

Your turn to define your Arduino type.

I was using a freeduino. But now I switched to an UNO R3 board. But how do I define the TX and RX pins , since there is no GSM.cpp in the libraries folder? Please reply asap

I may be wrong, but I am under the impression that the GSM library is specifically for the Arduino GSM shield.

If you really want to have a play around then the pins are defined in GSMSoftSerial.cpp, but while you are there note that there is a pin definition for RXINT - where you connect that on a SIM900 I'm at a loss to know.