Form api functions

• drupal_process_form
  Make the form processing
  Could be called by the classic [drupal_get_form] (http://api.drupal.org/api/drupal/includes%21form.inc/function/drupal_build_form/7) or it is an ajax call ajax_form_callback http://api.drupal.org/api/drupal/includes%21form.inc/function/drupal_process_form/7

• drupal_get_form
  Render a form with a given form_id, this function does not allow to pass value to the form In the signature of the function there is only $form_id and not $form_state Is calling drupal_build_form http://api.drupal.org/api/drupal/includes%21form.inc/function/drupal_get_form/7

• drupal_build_form
  Render a form and a $form_state array could be given http://api.drupal.org/api/drupal/includes%21form.inc/function/drupal_build_form/7