title: Need help with zend form validation
body: <p>I wanted to create an invitation form for user to signup. But the signup form is only for people have the special invitation code. So how can I set it in Zend form validation to check if the invitation code matches the code the user enter. The invitation code is the same for all the people that are invited.</p>
  
  <p>Here is the code I wrote.</p>
  
  <pre><code>                    $invitationElement = new Zend_Form_Element_Text('invitationCode');
                      $invitationElement-&gt;setLabel('Invitation Code');
                      $invitationElement-&gt;setRequired(true);
  </code></pre>
  
  <p>Thanks so much in advance</p>