Automatic light

int sensorPin = A0;   // select the input pin for ldr
int sensorValue = 0;  // variable to store the value coming from the sensor
void setup() {
 pinMode(2, OUTPUT);
 pinMode(3,OUTPUT);
 pinMode(4,OUTPUT);
 pinMode(5,OUTPUT);//pin connected to the led
 Serial.begin(9600); //sets serial port for communication
}
void loop() {
 // read the value from the sensor:
 sensorValue = analogRead(sensorPin);    
 Serial.println(sensorValue); //prints the values coming from the sensor on the screen
 if(sensorValue < 900)
 {  
 digitalWrite(2,HIGH);
 digitalWrite(3,HIGH);
 digitalWrite(4,HIGH);
 digitalWrite(5,HIGH);//turn led ON
 }
 else
 {    
   digitalWrite(2,LOW);
   digitalWrite(3,LOW);
   digitalWrite(4,LOW);
   digitalWrite(5,LOW);//turn led OFF
 }  
 delay(100);                  
}