const int buttonpin = 2;
const int led = 3;
int buttonState = 0;
void setup()
{
pinMode(buttonpin,INPUT_PULLUP);
pinMode(led, OUTPUT);
}

void loop()
{
buttonState = digitalRead(buttonpin);
 if(buttonState == LOW)
 {
 digitalWrite(led, HIGH);}
 else
 {
  digitalWrite(led, LOW);} 
}