int led1 =2;
int buttonPin =3;
int buttonState =0;

void setup()
{
pinMode(led1, OUTPUT);
pinMode(buttonPin, INPUT);
digitalWrite(led1, HIGH);  
digitalWrite(buttonPin, HIGH);  
}
void loop()
{
buttonState =digitalRead(buttonPin);
if (buttonState ==HIGH){
digitalWrite(led1, LOW);
}
else{
  digitalWrite(led1, HIGH);
}
}