int ldr=3;
int led=2;
void setup() 
{
  // put your setup code here, to run once:
pinMode(ldr,INPUT);
pinMode(led,OUTPUT);
Serial.begin(9600);
}
void loop() 
{
  // put your main code here, to run repeatedly:
int state=digitalRead(ldr);
if(state>0)
{
  digitalWrite(led,HIGH);
  Serial.println(state);

}
else
{
  digitalWrite(led,LOW);
   Serial.println(state);
}
}