int switchState = 0;

void setup() {
  // put your setup code here, to run once:
  pinMode(3, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(2, INPUT);

}


void loop() {
  // put your main code here, to run repeatedly:
  switchState = digitalRead(2);
  
  if (switchState == LOW){
    // if the the button is not pressed then do the following
    digitalWrite(3, HIGH); //Red light ON
    digitalWrite(4, LOW); //Yellow light OFF
    digitalWrite(5, LOW); //green light OFF
  }
  else {
    // if instead the button is pressed then do the following
    digitalWrite(3, LOW); //Red light OFF
    digitalWrite(4, LOW); //Yellow light OFF
    digitalWrite(5, HIGH); //green light ON
    delay(250); // WAIT FOR A QUARTER SECOND

    // toggle the LEDs
    digitalWrite(4, HIGH);
    digitalWrite(5, LOW);
    delay(250); // wait for a quarter second
  }

} // GO BACK TO THE BEGINNING OF THE LOOP