const int led = 8;
const int button = 7;
//note: reads LOW(0V) when button NOT pressed 
//      and HIGH(5V) when button IS pressed

void setup() {
  // put your setup code here, to run once:
  pinMode(led, OUTPUT);
  pinMode(button, INPUT);

  //turn off led intially
  digitalWrite(led, LOW);

}

void loop() {
  // put your main code here, to run repeatedly:

  while(digitalRead(button) == HIGH) // button pressed
  {
    digitalWrite(led, HIGH); // led on
  }
  while(digitalRead(button) == LOW) // button not pressed
  {
    digitalWrite(led, LOW); // led off
  }
}