int buttonState = 0;

void setup()
{
  pinMode(0, INPUT);
  pinMode(1, OUTPUT);
}

void loop()
{
  // read the state of the pushbutton
  buttonState = digitalRead(0);
  // check if pushbutton is pressed. if it is, the
  // button state is HIGH
  if (buttonState == HIGH) {
    digitalWrite(1, LOW);
  } else {
    digitalWrite(1, HIGH);
  }
  delay(10); // Delay a little bit to improve simulation performance
}