const int buttonPin=2;
const int ledPin=13;
int buttonState=0;
void setup() 
{
  pinMode(ledPin, OUTPUT);
  pinMode(buttonPin,INPUT);
  Serial.begin(9600);
}
void loop()  
{
 buttonState=digitalRead(buttonPin);
 Serial.println(buttonState);
 if(buttonState==LOW)
 {
  digitalWrite(ledPin, HIGH);
 }
 else
 { 
  digitalWrite(ledPin, LOW);
 }
}