title: Rails/Formtastic Newbie: Setting display field for referenced "select" box
body: <p>New <code>formtastic</code> user here.</p>
  
  <p>I have a relationship <code>user has_many clients</code></p>
  
  <p>In <code>formtastic</code>, if I do something such as</p>
  
  <pre><code>f.input :employer
  </code></pre>
  
  <p>it returns a select box of all employer object references. I'd like to display (last name, first name) instead. I'm sure this is very simple, but I can't figure out exactly how to do it.. Any help appreciated.</p>