void setup() {
  // put your setup code here, to run once:
pinMode(4,OUTPUT);
pinMode(5,OUTPUT);
pinMode(6,OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
 digitalWrite(6,HIGH);tone(4,1000,50);
 delay(100);
 digitalWrite(6,LOW);
 delay (100);
 digitalWrite(5,HIGH);
 delay(100);
 digitalWrite(5,LOW); 
 delay(100);
}