title: How to use the "required" attribute with a "radio" input field
body: <p>I am just wondering how to use the new HTML5 input attribute "required" in the right way on radio buttons. Does every radio button field need the attribute like below or is it sufficient if only one field gets it?   </p>
  
  <pre><code>&lt;input type="radio" name="color" value="black" required="required" /&gt;
  &lt;input type="radio" name="color" value="white" required="required" /&gt;
  </code></pre>