title: Routing error in Ruby on Rails 3
body: <p>I am new to Ruby on Rails
  I am getting this error</p>
  
  <blockquote>
    <p>uninitialized constant WelcomeController</p>
  </blockquote>
  
  <p>after creating the sample project. I enabled</p>
  
  <pre><code>root :to =&gt; 'welcome#index'
  </code></pre>
  
  <p>in routes.rb.</p>