int switch_on = 4;
int led_on = 1;
int led_off = 2;

void setup() {
  // put your setup code here, to run once:
pinMode(switch_on, INPUT);
pinMode(led_on, OUTPUT);
pinMode(led_off, OUTPUT);

}

void loop() {
  // put your main code here, to run repeatedly:
if(digitalRead(switch_on) == HIGH) {
  digitalWrite(led_on, HIGH);
  digitalWrite(led_off, LOW);

 } else { 
  digitalWrite(led_off, HIGH);
  digitalWrite(led_on, LOW);

 }
}