How to validate if a string in PHP only contains letters, single quotes and dash
<blockquote>
  <p><strong>Possible Duplicate:</strong><br>
  <a href="http://stackoverflow.com/questions/7385420/regex-to-allow-a-z-and">Regex to allow A-Z, - and &#39;</a>  </p>
</blockquote>



<p>I have a form that asks for a name, and the name must not contain any numbers but can have a (') or a (-) e.g O'Neal, O-man.</p>

<p>I've already used <code>is_string()</code> but it seems to be strict, does any one of you know how to validate a string that accepts those kinds of values?</p>
