int buttonState = 0; 

void setup()
{
  pinMode (D1, INPUT); 
  pinMode(D2, OUTPUT); 
  Serial.begin (9600); 
} 

void loop() 
{ 
  // read the state of the pushbutton value 
  buttonState = digitalRead(D1) ; 
  // check if pushbutton is pressed. if it is, the // buttonState is HIGH 
  if (buttonState == HIGH) { 
    // turn LED on 
    digitalwrite(D2, HIGH); 
    Serial.print("input is High"); 
  } else { 
    // turn LED off 
    digitalwrite(D2, LOW); 
    Serial. print ("input is low"); 
  }
  delay(10); // Delay a little bit to improve simulation performance
}