new_contents: import os
  
  def save_screenshot(driver, name, save_location):
    # Make sure the path exists.
    path = os.path.abspath(save_location)
    if not os.path.exists(path):
      os.makedirs(path)
    full_path = '%s/%s' % (path, name)
    driver.save_screenshot(full_path)
    return full_path
  
  from selenium import webdriver
  from selenium.webdriver.chrome.options import Options
  
  driver = webdriver.Firefox()
  driver.get('http://www.app2b.cn/')
  driver.set_window_size(width_needed, height_needed)
  screenshot = take_screenshot(driver, 'app2b_firefox.png', 'screenshots')
  print "Screenshot saved to: %s" % screenshot
  driver.quit()
  
  chrome_options = Options()
  chrome_options.add_argument("--disable-extensions")
  chrome_options.add_argument("--window-size=320,480")
  chrome_options.add_argument("--user-agent='Mozilla/5.0 (iPhone; CPU iPhone OS 5_0 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A334 Safari/7534.48.3'")
  driver2 = webdriver.Chrome(chrome_options=chrome_options)
  driver2.get('http://www.app2b.cn/')
  screenshot = save_screenshot(driver2, 'app2b_chrome.png', 'screenshots')
  print "Screenshot saved to: %s" % screenshot
  driver2.quit()
  
subject: add selenium samplel code