import RPi.GPIO as GPIO
import time
GPIO.setwarnings(False)
GPIO.setmode(GPIO.BOARD)
GPIO.setup(11, GPIO.IN)         
GPIO.setup(3, GPIO.OUT)         
while True:
	i=GPIO.input(11)
	if i==0:                 
		print "No intruders",i
		GPIO.output(3, 0)  
		time.sleep(0.1)
	elif i==1:               
		print "Intruder detected",i
		GPIO.output(3, 1)  
		time.sleep(0.1)