const int buttonPin = 4;
const int ledPin1 = 10;
const int ledPin2 = 11;

int buttonState = LOW;
int lastButtonState = LOW;

unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 50;

int mode = LOW;

void setup() {
  pinMode(buttonPin, INPUT);
  pinMode(ledPin1, OUTPUT);
  pinMode(ledPin2, OUTPUT);
}

void loop() {
  int reading = digitalRead(buttonPin);

  if (reading != lastButtonState){
    lastDebounceTime = millis();
  }

  if((millis() - lastDebounceTime) > debounceDelay) {
    if(reading != buttonState){
      buttonState = reading;

      if (buttonState == HIGH){
        mode++;
        mode = mode % 3;
      }
    }
  }

  lastButtonState = reading;

  switch (mode){

    case 0:
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, LOW);
    break;

    case 1:
    digitalWrite(ledPin1, (millis()/1000) % 2);
    digitalWrite(ledPin2, LOW);
    break;

    case 2:
    digitalWrite(ledPin1, (millis()/1000) % 2);
    digitalWrite(ledPin2, (millis()/2000) % 2);
    break;

  }

}