---

int n=0,b;

void setup(){
  pinMode(2,INPUT_PULLUP);
  pinMode(9,OUTPUT);
}

void loop(){
  if(!digitalRead(2)){
    delay(50);
    if(!digitalRead(2)){
      n++;
      if(n==3) for(b=0;b<=255;b++) analogWrite(9,b),delay(10);
      if(n==4) analogWrite(9,0),n=0;
      while(!digitalRead(2));
    }
  }
}