Usernode, validating fields

Hi,

I'm wondering about to validate input form created by myself, all of these content types are associated to node type by nodefamily, each user has capability to create content type depending on his roles.

I have several content types created by me, they are assigned to usernode, to show them in user profile with tabs.

Every content type has a form itself, I want to validate these input fields.

I'm trying to include to use drupal standard validate function, but I can't use $form_values, how can I get them?

Where have I to insert the form validate function? I've tryed to redirect from the function alter_form of node.module, to a custom function, but $form_values aren't available for this function. Can anyone help me, and newcomers to these modules functionalities?

thanks

neruda001