int LED = 13;
int Buzz = 9;
int LDR = A0;
void setup() {
  // put your setup code here, to run once:
  //Serial.begin(9600);
pinMode(LED , OUTPUT);
pinMode(Buzz , OUTPUT);
pinMode(LDR , INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
int sig;
sig = analogRead(LDR);
//Serial.println(sig);

if (sig >= 400) {
  tone(Buzz , 1000);
  digitalWrite(LED , HIGH);
  delay(500);
  noTone(Buzz);
  digitalWrite(LED , LOW);
    delay(500);
  //Serial.println("Alarm Activated");
} else {
  noTone(Buzz);
  digitalWrite(LED , LOW);
 // Serial.println("Alarm Deactivated");
}
}