int ledPin = 2;
  int button = 7;

void setup() {
  // put your setup code here, to run once:

  pinMode(ledPin, OUTPUT);
  pinMode(button, INPUT);

}

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

if (digitalRead(button) == 1){
  digitalWrite(ledPin, HIGH);
  delay(500);
  digitalWrite(ledPin, LOW);
}

}