int ledpin=12;
int buttonpin=10;
int buttonState;

void setup() {
  // put your setup code here, to run once:
  pinMode(12, OUTPUT);
  pinMode(10, INPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  buttonState=digitalRead(buttonpin);
  if(buttonState==LOW)
  {
    digitalWrite(12, HIGH);
    delay(1000);
    digitalWrite(12, LOW);
    delay(1000);
  }
  else
  {
    digitalWrite(12, LOW);
  }
}