title: Alphabetic Regex in HTML5
body: <p>I'm really new to regex but I need to find a way to add a filter to a HTML5 form:</p>
  
  <pre class="lang-html prettyprint-override"><code>&lt;input type="text" required="true" name="firstname" pattern="WHAT DO I PUT HERE"&gt;
  </code></pre>
  
  <p>Could anyone help me with what to put in the pattern attribute, for example</p>
  
  <p>Accepted:</p>
  
  <ul>
  <li><code>John</code></li>
  <li><code>Frank</code></li>
  </ul>
  
  <p>Not accepted:</p>
  
  <ul>
  <li><code>Ke$ha</code></li>
  <li><code>B0B</code></li>
  </ul>
  
  <p>(Only alphabetic characters are accepted.)</p>