const int LED=3;
const int sw =4;

void setup() {
  pinMode(LED,OUTPUT);
  pinMode(sw,INPUT);

  // put your setup code here, to run once:

}

void loop()
 {
  int data;
  data=digitalRead(sw);
  if (data==1)
    {
      digitalWrite(3, HIGH);
    }
    else
    {
      digitalWrite(3, LOW);
    }
  // put your main code here, to run repeatedly:

}