// Example 03A: Turn on LED when the button is pressed 
// and keep it on after it is released 
//
// Copy and paste this example into an empty Arduino sketch

#define LED  13  // the pin for the LED 
#define BUTTON 7 // the input pin where the
                 // pushbutton is connected
int val = 0;     // val will be used to store the state
                 // of the input pin 
int state = 0;   // 0 = LED off while 1 = LED on 

void setup() { 
  pinMode(LED, OUTPUT);   // tell Arduino LED is an output 
  pinMode(BUTTON, INPUT); // and BUTTON is an input 
} 


void loop() { 
  val = digitalRead(BUTTON); // read input value and store it 

  // check if the input is HIGH (button pressed) 
  // and change the state 
  if (val == HIGH) { 
    state = 1 - state; 
  } 


  if (state == 1) {      
    digitalWrite(LED, HIGH); // turn LED ON 
  } else { 
    digitalWrite(LED, LOW); 
  } 
}