int led=4;
int boton1=2;
int boton2=15;


void setup()
{  
  pinMode(led, OUTPUT);
  pinMode(boton1, INPUT);
  pinMode(boton2, INPUT);
}

void loop()
{

  while(digitalRead(boton1))
  { 
  digitalWrite(led, HIGH);
  }
  if (digitalRead(boton2))

  { 
  digitalWrite(led, LOW);
  }

}