title: NameError: name 'driver' is not defined for Selenium
body: <p>I get this error: NameError: name 'driver' is not defined
  When i run my code in python. 
  What i want is call the module Navigation for go back on my page.</p>
  
  <pre><code>I try some code like this:
  driver = webdriver.Firefox()
  
  from selenium import webdriver
  driver = webdriver.Chrome(executable_path= r'C:\\Utility\\BrowserDrivers\\chromedriver.exe')
  </code></pre>
  
  <p>My code: </p>
  
  <pre><code>from selenium import webdriver   
  
  # For using sleep function because selenium 
  # works only when the all the elemets of the 
  
  # page is loaded. 
  import time 
  
  from selenium.webdriver.common.keys import Keys 
  from selenium import webdriver
  # Apertura firefox (OK)
  browser = webdriver.Firefox() 
  browser.get('https://www.presearch.org/login') 
  
  
  # Inserimento mail (OK)
  
  user = browser.find_elements_by_xpath('/html/body/div[1]/div[2]        /div/div[2]/div[3]/div[1]/form/div[1]/input') 
  user[0].click() 
  user[0].send_keys('my_mail') 
  
  # Inserimento password (OK) 
  
  
  user = browser.find_elements_by_xpath('/html/body/div[1]/div[2]        /div/div[2]/div[3]/div[1]/form/div[2]/div/input') 
  user[0].click() 
  user[0].send_keys('My_pass')
  
  LOG = browser.find_elements_by_xpath('/html/body/div[1]/div[2]  /div/div[2]/div[3]/div[1]/form/div[3]/div[2]/button') 
  LOG[0].click() 
  print("Login Sucessfull") 
  time.sleep(5) 
  
  
  # Inserimento testo + coin (OK) 
  elem = browser.find_element_by_xpath("//*[@id=\"search\"]")  
  elem.click() 
  elem.clear() 
  
  elem.send_keys("Geeks for geeks ") 
  
  elem.send_keys(Keys.RETURN) 
  
  print("Testo inserito, coin guadagnato") 
  
  # Ritorno pagina
  
  driver.navigate().back();
  </code></pre>
  
  <p>What i wannt is, for the last part of my program, automaticly go back with the function driver.navigate().back(); without get the error below </p>