int IR=2;
int buzzer=13;
void setup() {
 // put your setup code here, to run once:
 Serial.begin(9600);
 pinMode(IR, INPUT);
 pinMode(buzzer,OUTPUT);
}
void loop() {
     // put your main code here, to run repeatedly:
        int statussensor=digitalRead(IR);
        if(statussensor==1) digitalWrite(buzzer,LOW);
        else digitalWrite(buzzer,HIGH);
}