I have a Drupal module page where I am populating a form with a drop-down that contains a list of available parts of a set of files that the user can upload. Once the user uploads a file of a certain type, it removes that option from the list, and when all the available files are uploaded the form will not be rendered. The problem is that Drupal is drawing the form before it carries out the submit action, so it appears to the user that the operation didn't work until they reload the page. What is the common way to deal with this? Setting form_state['redirect'] to go to the page doesn't seem to work.