LED script (Not Working)

#! /usr/bin/python Imports

import time
import RPi.GPIO as GPIO

# Set up GPIO
# LEDs on 4, 17, 18, 22, 23, 27 (BCM numbering rev2)
GPIO.setmode(GPIO.BCM)
GPIO.setwarnings(False)

#Set up GPIO input/output status
GPIO.setup(4, GPIO.OUT)
GPIO.setup(17, GPIO.OUT)
GPIO.setup(18, GPIO.OUT)
GPIO.setup(22, GPIO.OUT)
GPIO.setup(23, GPIO.OUT)
GPIO.setup(27, GPIO.OUT)

# Clear all segments before start
GPIO.output(4,False)
GPIO.output(17,False)
GPIO.output(18,False)
GPIO.output(22,False)
GPIO.output(23,False)
GPIO.output(27,False)
time.sleep(1)

def main():
  var = 1
  while var == 1 :
    GPIO.output(4, True)
    GPIO.output(17, True)
    GPIO.output(18, True)
    GPIO.output(22, True)
    GPIO.output(23, True)
    GPIO.output(27, True)
    time.sleep(2)
    GPIO.output(4, False)
    GPIO.output(17, False)
    GPIO.output(18, False)
    GPIO.output(22, False)
    GPIO.output(23, False)
    GPIO.output(27, False)

try:
  main()
except:
  print "Shutting down..."
  GPIO.output(4,False)
  GPIO.output(17,False)
  GPIO.output(18,False)
  GPIO.output(22,False)
  GPIO.output(23,False)
  GPIO.output(27,False)