title: Conditional field using dynamic vocabularies to custom fields on @@register
body: <p>I'm following <a href="http://pypi.python.org/pypi/collective.examples.userdata" rel="nofollow">collective.examples.userdata</a> to add some custom fields on the register form.</p>
  
  <p>I want to add two fields, one for state and another for city, where the second load content based on the previously selected state.</p>
  
  <p>My question is how it is possible, can do this only with the schema, using <a href="http://developer.plone.org/forms/vocabularies.html#dynamic-vocabularies" rel="nofollow">dynamic vocabularies</a> or is need to edit registration form? How can I do it?</p>
  
  <p>Another issue is how to load the registration form in a portlet. Is Possible fill the @@register viewlet?</p>
  
  <p>Thanks!</p>