power line aurduino code

/*
 * Project name:
     Power Line Modem
 * Copyright
     (c) Researchdesignlab.com
 * Description:
    
 * Test configuration:
     MCU:             ATMEGA328
     Dev.Board:       Arduino uno
     Oscillator:      16 MHz
     Software:        Arduino

*/


int relay=10;       // intiz RELAY pin
char rec;

void setup()
{
  Serial.begin(9600);      // initialize the serial communications
  pinMode(relay,OUTPUT);
}


void loop()
{
  digitalWrite(relay,LOW);  
  if(Serial.available())
  {
    rec=Serial.read();        //wait to recive the data from power line modem
    if(rec=='1')
    {
      digitalWrite(relay,HIGH);
      delay(100);                 //time delay
    }
    if(rec=='2')
    {
      digitalWrite(relay,LOW);
      delay(100);
    }
  }
}