const int buttonpin=13;
const int ledpin=2;
int buttonstate=0;
void setup(){
  pinMode(ledpin, OUTPUT);
  pinMode(buttonpin, INPUT);
}
void loop(){
  buttonstate=digitalRead (buttonpin);
  if (buttonstate==LOW)
  {
digitalWrite(ledpin, HIGH);
  }
  else
  {
digitalWrite(ledpin, LOW);
}
}