Arduino robot LDR

int LDR = A5;
int lux = 0; // Note the value from the sensor is not the real lux value ;-) max value is 1023.
void checkLight() {
  lux = analogRead(LDR);

  if (lux < 400) {
    analogWrite(headLights, 255);
  } else {
    analogWrite(headLights, 10);
  }
}