This video (video 1 of 5 on Adding Backend Actions) looks at the changes to the display of the helloworld messages.
Web pages referenced include:
https://stackoverflow.com/questions/547821/two-submit-buttons-in-one-form
https://docs.joomla.org/Supporting_SEF_URLs_in_your_component
https://docs.joomla.org/How_to_add_CSRF_anti-spoofing_to_forms
