attempted blink sketch redux

import time
import RPi.GPIO
LEDPin = 4
RPi.GPIO.setmode(RPi.GPIO.BCM)
RPi.GPIO.setup(pin, RPi.GPIO.OUT, initial=RPi.GPIO.LOW)

while(True):
    RPi.GPIO.output(LEDPin, RPi.GPIO.HIGH)
    time.sleep(0.5)
    RPi.GPIO.output(LEDPin, RPi.GPIO.LOW)
    time.sleep(0.5)