int j;
int dt=500;
int buzzpin=3;





void setup() {
  // put your setup code here, to run once:
pinMode(buzzpin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
for (j=1;j<=100;j=j+1); {
digitalWrite(buzzpin, HIGH);
delay(dt);
digitalWrite(buzzpin, LOW);
}
for (j=1;j<=100;j=j+1); {
digitalWrite(buzzpin, HIGH);
delay(dt);
digitalWrite(buzzpin, LOW);
}
}