int switchState=0;
void setup() {
  // put your setup code here, to run once:
pinMode(2, INPUT);
pinMode(3, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
switchState=digitalRead(2);
if (switchState==0)
{
  digitalWrite(3, LOW);
}
else
{
  digitalWrite(3, HIGH);
}
}