[development] Using drupal_execute

I can't get this form to programatically display (not part of any callback) and wait for a submission. I call it, and it fires the function that creates the form array, but I never see the form unless I put 'exit' after it. When using drupal_execute, is the 'values' array of $form_state required, with each field named? My $form_state array is empty. I didn't think I needed the enumerated 'values' array because I assumed (yes, I know...) that the #default entries in the form elements accomplish what I need.