title: Input elements not being posted with HTML5
body: <p>I'm working on a test HTML5 login form and have the form set up like so:</p>
  
  <pre><code>&lt;form id="login" method="POST" action="&lt;?php echo $_SERVER['PHP_SELF'] ?&gt;"&gt;
      &lt;h1&gt;Log In&lt;/h1&gt;
      &lt;fieldset id="inputs"&gt;
          &lt;input id="username" type="text" placeholder="Username" autofocus required&gt;   
          &lt;input id="password" type="password" placeholder="Password" required&gt;
      &lt;/fieldset&gt;
      &lt;fieldset id="actions"&gt;
          &lt;input type="submit" id="submit" name="submit_data" value="Log in"&gt;
      &lt;/fieldset&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>When clicking Submit, the form is posted back to the same page.  When I print the array of POSTed elements, I'm only seeing one for 'submit_data'.   'username' and 'password' are not coming through. </p>
  
  <p>Where am I going wrong?  </p>