int ldr=7;
int x;
int led = 13;

void setup() 
{
 Serial.begin(9600);
 pinMode(7, INPUT);
 pinMode(13, OUTPUT);  
  // put your setup code here, to run once
}

void loop()
 {
  x=digitalRead(7);
  Serial.println(x);

if(x == HIGH)
{
  digitalWrite(13, HIGH);
  }
if(x == LOW)  
{

    digitalWrite(13, LOW);

  }  // put your main code here, to run repeatedly:

}