auto led on/off

const int relayPin = 13;
const int ldrPin = A0;


void setup() {

  Serial.begin(9600);
  pinMode(relayPin, OUTPUT);
  pinMode(ldrPin, INPUT);
}

void loop() {

  int ldrStatus = analogRead(ldrPin);


   if (ldrStatus <=400) {

    digitalWrite(relayPin, LOW);
    Serial.println("LDR is DARK, LED is ON");

   }
  else {

    digitalWrite(relayPin, HIGH);
    Serial.println("---------------");
  }
}