   buttonState = digitalRead(buttonPin);
 
   // check if the pushbutton is pressed.
-  // if it is, the buttonState is HIGH:
-  if (buttonState == HIGH) {     
+  // if it is, the buttonState is LOW:
+  if (buttonState == LOW) {     
     // turn LED on:    
     digitalWrite(ledPin, HIGH);  
   } 


// constants won't change. They're used here to 
// set pin numbers:
const int buttonPin = 2;     // the number of the pushbutton pin
const int ledPin =  13;      // the number of the LED pin

// variables will change:
int buttonState = 0;         // variable for reading the pushbutton status

  // initialize the LED pin as an output:
  pinMode(ledPin, OUTPUT);      
  // initialize the pushbutton pin as an input:
  pinMode(buttonPin, INPUT_PULLUP);     
}

void loop(){
