Type text in the form and then press Submit. This web page is a tool to diagnose form <Submit> functionality by examining what a form within a web page sends to webserver.
Repalce the form action property with
then run the page (open in a browser), and press the Submit button. Analyze the diagnostic report and if satisfactory put your own action back to the form, if not satisfactory make your changes and rerun.
The data filled in must be helpful for you to recognize the elements in the generated report.