title: Determine if a character is alphabetic
body: <p>Having problems with this.</p>
  
  <p>Let's say I have a parameter composed of a single character and I only want to accept alphabetic characters. How will I determine that the parameter passed is a member of the latin alphabet (<code>a</code>–<code>z</code>)?</p>
  
  <p>By the way Im using PHP Kohana 3.</p>
  
  <p>Thanks.</p>