const int BUTTON = 4;
const int LED = 3;
int BUTTONstate = 0;


void setup()
 {
    pinMode(BUTTON, INPUT_PULLUP);
    pinMode(LED, OUTPUT);  
 }

void loop()
 {
  BUTTONstate = digitalRead(BUTTON);

  if (BUTTONstate == HIGH)
   {
    for (int i=0; i <= 1 ; i++) {
      digitalWrite(LED, HIGH);
      delay(100);
      digitalWrite(LED, LOW);
    }
    
   }
   else {
    digitalWrite(LED, LOW);
   }
 }