input: 
  from selenium import webdriver
  from selenium.webdriver.common.keys import Keys
  import time
  
  def automate_login(url: str, username_field: str, password_field: str, submit_button: str) -> None:
      """ Automates the login process on a given website.
      >>> automate_login('http://www.example.com', 'username', 'password', 'submit')
      'Login successful!'
      """
      # Initialize web driver
      driver = webdriver.Chrome()
  
      # Navigate to the target web page
      driver.get(url)
  
      # Locate username field
      username = driver.find_element_by_name(username_field)
  
      # Enter username
      username.send_keys('username')
  
      # Locate password field
      password = driver.find_element_by_name(password_field)
  
      # Enter password
      password.send_keys('password')
  
      # Locate submit button
      submit_button = driver.find_element_by_name(submit_button)
  
      # Click submit button
      submit_button.click()
  
      # Wait for login process to complete
      time.sleep(5)
  
      # Print login status
      print('Login successful!')
  
      driver.close()
  
  
output:     # Initialize web driver
      driver = webdriver.Chrome()
  
      # Navigate to the target web page
      driver.get(url)
  
      # Locate username field
      username = driver.find_element_by_name(username_field)
  
      # Enter username
      username.send_keys('username')
  
      # Locate password field
      password = driver.find_element_by_name(password_field)
  
      # Enter password
      password.send_keys('password')
  
      # Locate submit button
      submit_button = driver.find_element_by_name(submit_button)
  
      # Click submit button
      submit_button.click()
  
      # Wait for login process to complete
      time.sleep(5)
  
      # Print login status
      print('Login successful!')
  
      driver.close()