title: Drupal textfield input limiting
body: <p>My client wants to limit the input into a textfield to 16 words - I have no idea how to achieve this.</p>
  
  <p>In addition, he wants to disble characters from being part of the input.
  In other words, allow only 16 words and with no special characters.</p>
  
  <p>Can anyone give me some ideas?</p>