int PIR=5;
int LED=13;
void setup()
{
  pinMode(13,OUTPUT);
  pinMode(5,INPUT);
  Serial.begin(9600);
}

void loop() 
{
  if (digitalRead(PIR)==HIGH)
  {
    digitalWrite(13,HIGH);
    delay(10);
  }
  else
  {
    digitalWrite(13,LOW);
    delay(10);
  }
}