int switchState = 0;
void setup(){
  pinMode(3,OUTPUT);
  pinMode(4,OUTPUT);
  pinMode(5,OUTPUT);
  pinMode(2,INPUT);
}
void loop(){
  switchState = digitalRead(2);
  // this is a comment
  if (switchState == LOW) {
  // the button is not pressed
    digitalWrite(3, HIGH); // green LED
    digitalWrite(4, LOW);  // red LED
    digitalWrite(5, LOW);  // red LED
  }
  else {  // the button is pressed
    digitalWrite(3, LOW);
    digitalWrite(4, LOW);
    digitalWrite(5, HIGH);
    delay(250);
    // toggle the LEDs
    digitalWrite(4, HIGH);
    digitalWrite(5, LOW);
    delay(250); // wait for a quarter second
  }
} // go back to the beginning of the loop