#include <SoftwareSerial.h>

SoftwareSerial mySerial(4,5); // RX, TX

void setup()  
{
 // Open serial communications and wait for port to open:
  Serial.begin(9600);
  Serial.println("Started");
 
 // set the data rate for the SoftwareSerial port
  mySerial.begin(9600);
  mySerial.println("AT+CMGR=5");
}

void loop() // run over and over
{
  if (mySerial.available())
    Serial.write(mySerial.read());
  if (Serial.available())
    mySerial.write(Serial.read());
}