op, are you aware that javascript is not perl? Do you know what language the onsubmit event handler comes from? You seem to have skimmed over a few steps in your web programming education:

1) Your html is atrocious, so you need to read a modern text book on proper html.

2) You don't have the skill yet to include any javascript anywhere on your html pages. So for the next year, forget you ever heard the word javascript. If you want to learn server side programming, then concentrate on that. If you want to learn client side programming, then concentrate on javascript. But whatever you do, don't try to learn server side programming and javascript at the same time.

3) You don't call perl scripts with javascript onsubmit event handlers.

4) For practice, you need to create a basic html page with one form field and a submit button. When the user clicks on the submit button, the form should request your perl script. Your perl script should return an html page that says, "You entered: ...." How is that done? Read five beginning CGI tutorials, and then come back if you still have any questions.