arduino uno com12

In Arduino Uno, com12 board, already Bluetooth code is installed or not?

I am doing the project based on robot using Arduino.

I uploaded already one code, it is wrong and I want to upload another code in that. What I have to do?

 int LMotorUp = 10;
 int LMotorDn = 11;
 int RMotorUp = 8;
 int RMotorDn = 9;

void setup()
{
  Serial.begin(9600);
  pinMode(LMotorUp,OUTPUT);
  pinMode(LMotorDn,OUTPUT);
  pinMode(RMotorUp,OUTPUT);
  pinMode(RMotorDn,OUTPUT);
  Serial.println("Arduino string");
}
void loop()
{
  if(Serial.available()>0)
  {
    int input = Serial.read();
    switch(input)
    {
      case 'w':MoveF();
      break;
      case 's':MoveB();
      break;
      case 'a':MoveL();
      break;
      case 'd':MoveR();
      break;
      case 'x':Stop();
      break;
      default:break;
    }
  }
  delay(50);
}

void MoveF()
{
  digitalWrite(LMotorUp,HIGH);
  digitalWrite(LMotorDn,LOW);
  digitalWrite(RMotorUp,HIGH);
  digitalWrite(RMotorDn,LOW);
}
void MoveB()
{
  digitalWrite(LMotorUp,LOW);
  digitalWrite(LMotorDn,HIGH);
  digitalWrite(RMotorUp,LOW);
  digitalWrite(RMotorDn,HIGH);
}
void MoveL()
{
  digitalWrite(LMotorUp,LOW);
  digitalWrite(LMotorDn,LOW);
  digitalWrite(RMotorUp,HIGH);
  digitalWrite(RMotorDn,LOW);
}
void MoveR()
{
  digitalWrite(LMotorUp,HIGH);
  digitalWrite(LMotorDn,LOW);
  digitalWrite(RMotorUp,LOW);
  digitalWrite(RMotorDn,LOW);
}
void Stop()
{
  digitalWrite(LMotorUp,LOW);
  digitalWrite(LMotorDn,LOW);
  digitalWrite(RMotorUp,LOW);
  digitalWrite(RMotorDn,LOW);
}