int sensorpin = A0;
int light = 13;

void setup()
{
  Serial.begin(9600);
  pinMode(light, OUTPUT);
}

void loop()
{
  int ldr = analogRead(sensorpin);
  Serial.println(ldr);
  if(ldr>500)
  {
    digitalWrite(light, HIGH);
    Serial.println("Light ON");
  }
  else
  {
    digitalWrite(light, LOW);
    Serial.println("Light off");
  }
}