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);
      }
      }