Validating fields created with CCK

Hello:

I am maintaining a site with the following modules installed:
1. formtweaker 2. cck 3. views 4. location

I have created a content type ACTION with input form fields inserted by formtweaker (i.e. vocabulary sections, vocabulary fields, vocabulary others). I don't know how to do validation on these fields. Same issue with Location fields also, I need to do validation on them.

When I created form_alter for this form_id, I don't even see these fields...strange...can anyone help me? Thanks.