avrdude: stk500_getsync(): not in sync: resp=0x00

Hi, I am new to the arduino family and only started with it a couple of weeks back. I am trying your tutorials with a Uno and a Simcom sim900 GPRS board but the above error keeps on popping up. The shield is registered as the net led blinks every 3000ms.

Please help!

Thanks CS

(deleted)

Hi,
Managed to sort out the error problem,it was the TX and RX jumper setting, but the program does not seem to run passed the "sms message sender" line.
It does not give me the "READY" message in the serial monitor so I would imagine it gets stuck somewhere.
[code/*
 SMS sender
 
 This sketch, for the Arduino GSM shield,sends an SMS message 
 you enter in the serial monitor. Connect your Arduino with the 
 GSM shield and SIM card, open the serial monitor, and wait for 
 the "READY" message to appear in the monitor. Next, type a 
 message to send and press "return". Make sure the serial 
 monitor is set to send a newline when you press return.
 
 Circuit:
 * GSM shield 
 * SIM card that can send SMS
 
 created 25 Feb 2012
 by Tom Igoe
 
 This example is in the public domain.
 
 http://arduino.cc/en/Tutorial/GSMExamplesSendSMS
 
 */

// Include the GSM library
#include <GSM.h>

#define PINNUMBER ""

// initialize the library instance
GSM gsmAccess;
GSM_SMS sms;

void setup()
{
  // initialize serial communications and wait for port to open:
  Serial.begin(9600);
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only
  }
  
  Serial.println("SMS Messages Sender");

  // connection state
  boolean notConnected = true;

  // Start GSM shield
  // If your SIM has PIN, pass it as a parameter of begin() in quotes
  while(notConnected)
  {
    if(gsmAccess.begin(PINNUMBER)==GSM_READY)
      notConnected = false;
    else
    {
      Serial.println("Not connected");
      delay(1000);
    }
  }
  
  Serial.println("GSM initialized");A
}

void loop()
{

  Serial.print("Enter a mobile number: ");
  char remoteNum[20];  // telephone number to send sms
  readSerial(remoteNum);
  Serial.println(remoteNum);
    
  // sms text
  Serial.print("Now, enter SMS content: ");
  char txtMsg[200];
  readSerial(txtMsg);
  Serial.println("SENDING");
  Serial.println();
  Serial.println("Message:");
  Serial.println(txtMsg);
  
  // send the message
  sms.beginSMS(remoteNum);
  sms.print(txtMsg);
  sms.endSMS(); 
  Serial.println("\nCOMPLETE!\n");
}

/*
  Read input serial
 */
int readSerial(char result[])
{
  int i = 0;
  while(1)
  {
    while (Serial.available() > 0)
    {
      char inChar = Serial.read();
      if (inChar == '\n')
      {
        result[i] = '\0';
        Serial.flush();
        return 0;
      }
      if(inChar!='\r')
      {
        result[i] = inChar;
        i++;
      }
    }
  }
}]

Please help