attempt at question before submit button is revealed

Hi, I have a simple page with a text box (for short essay type answer) with a conclusion button and corresponding text and a submit button.

I am trying to add an alert to the submit button if no attempt has been made to answer the question by adding text to the text field. If text has been entered then the submit button works as normal... it posts.

I have attached the Lectora file.

Any help would be great.

Thanks