title: document.getElementsByTagName not working
body: <p>I would like to use <code>document.getElementsByTagName('input')</code>
  to set as required (or unset it) for a list of inputs.
  is it possible?</p>
  
  <p>I've tried:</p>
  
  <pre><code>document.getElementsByTagName('input').required = false;
  </code></pre>
  
  <p>or (for a different purpose)</p>
  
  <pre><code>document.getElementsByTagName('input').value = ""
  </code></pre>
  
  <p>but it doesn't seem work.</p>
  
  <p>Moreover: is it possible to catch a certain type of input (i.e. text or radio)?</p>
  
  <p>Thank you!!!
  ObOnKen</p>