Dynamic Laser Tripwire/Alarm

1const int threshold = 920;
2const int Laser = 9;
3const int Led/Buzzer  = 12;
4bool Alarm = false;
5
6void setup() {
7  // put your setup code here,  to run once:
8  Serial.begin(9600);
9  pinMode(Laser, OUTPUT);
10  digitalWrite(Laser,  HIGH);
11}
12
13void loop() {
14  // put your main code here, to run repeatedly:
15  int Value = analogRead(A0);
16  Serial.println(Value);
17  if(Value < 800){
18    tone(12, 4000);
19  }else if(Value > 800){
20    noTone(12);
21  }
22 
23  
24}