Arduino GSM interface problem

Recently i happened buy a GSM module ( SIM900 ) and an arduino uno and uploaded the following code that i got from GitHub - meirm/SerialGSM: Serial GSM class for arduino.. .

#include <SerialGSM.h>
#include <SoftwareSerial.h>
SerialGSM cell(2,3);

boolean sendonce=true;
void setup(){
  Serial.begin(9600);
  cell.begin(9600);
  cell.Verbose(true);
  cell.Boot();
  cell.DeleteAllSMS();
  cell.FwdSMS2Serial();
 }


void loop(){
  if (cell.ReceiveSMS()){
     Serial.print("Sender: ");
     Serial.println(cell.Sender());
     Serial.print("message: ");
     Serial.println(cell.Message());
     cell.DeleteAllSMS();
  }
}

The only output i am getting when i receive the message is…

+CMTI: "SM",1

if 2nd sms is received,

+CMTI: "SM",2

But i am not gettting the sender number or the message.
What has gone wrong? Can anyone help me? I have to submit the project next week… :cold_sweat: =(