title: Selenium/Ruby unknown driver, firefox
body: <p>I wrote a selenium test that I have working in chrome, I'm trying to get selenium to run the test in every browser. When I try and access firefox I get an error though.</p>
  
  <p>Code up to the error...</p>
  
  <pre><code>require "rubygems"
  require "selenium-webdriver"
  
  driver = Selenium::WebDriver.for :Firefox
  </code></pre>
  
  <p>I get the following error on the line where driver is declared...</p>
  
  <pre><code>/Users/username/.rvm/gems/ruby-2.1.0/gems/selenium-webdriver-2.39.0/lib/selenium/webdriver/common/driver.rb:49:in 'for': unknown driver: :Firefox (ArgumentError)
  from /Users/samuelowens/.rvm/gems/ruby-2.1.0/gems/selenium-webdriver-2.39.0/lib/selenium/webdriver.rb:67:in 'for'
  from test.rb:47:in `&lt;main&gt;'
  </code></pre>
  
  <p>Any idea why that might be and how to fix it? Is there an easy way to write a selenium test and check it in multiple browsers? Thanks.</p>