title: Remove all label elements in JavaScript
body: <p>In my application, I check if the user's browser is <a href="http://www.w3.org/TR/html5/" rel="nofollow">HTML5-capable</a> and is able to display <a href="http://dev.w3.org/html5/spec/common-input-element-attributes.html#the-placeholder-attribute" rel="nofollow">placeholders</a> in input fields (using <a href="http://www.modernizr.com/" rel="nofollow">Modernizr</a>). If so, I want to remove all <code>labels</code> from the HTML document in an automatized way, but I really don't know how.</p>
  
  <p>In layman terms, if the user's browser supports placeholders I'd like to turn this:</p>
  
  <pre><code>&lt;label for="email"&gt;
    Email:
  &lt;/label&gt;
  &lt;input type="email" id="email" placeholder="Your email"&gt;
  </code></pre>
  
  <p>Into this -in every occurrence-:</p>
  
  <pre><code>&lt;input type="email" id="email" placeholder="Your email"&gt;
  </code></pre>
  
  <p>All I have is:</p>
  
  <pre><code>if (Modernizr.input.placeholder) {
    // Remove all labels from the HTML document
  }
  </code></pre>
  
  <p>Until now I assigned <code>id</code>s to the labels and removed them one by one, but I'd like a more efficient way to do it.</p>