title: Can an empty URL parameter be passed to my controller?
body: <p>Let's say my controller function is expecting 2 parameters: page_name, and user_name</p>
  
  <p>The URL would be in the format <a href="http://mysite.com/controller_name/function_name/page_name/user_name" rel="nofollow">http://mysite.com/controller_name/function_name/page_name/user_name</a></p>
  
  <p>Assuming that sometimes I can have a blank user_name, and other times I can have blank page_name, can I pass a blank page_name by loading this URL?
  <a href="http://mysite.com/controller_name/function_name//user_name" rel="nofollow">http://mysite.com/controller_name/function_name//user_name</a></p>
  
  <p>If the controller function is:</p>
  
  <pre><code>function function_name($page_name="default", $user_name=null) 
  ...
  </code></pre>
  
  <p>Would the $page_name value be "default" for the 2nd URL stated above?</p>