const int led = 4;
const int button = 3;

void setup() {
  // put your setup code here, to run once:
  pinMode(led, OUTPUT);
  pinMode(button, INPUT_PULLUP);
  digitalWrite(led, HIGH);
}

void loop() {
  // put your main code here, to run repeatedly:

  while(digitalRead(button))
  {
    digitalWrite(led, LOW);
  }
}