Difficult to see how it verifies when you have 3 different <doctype ...> statements
and no ending </body> or </html> tags.
Why are you using definitions from 1999 when you have a 2020 browser?
Why are you testing the first name to be greater than 39? Is this for a prison inmate?
What are you doing with the 'onsubmit' condition when you don't return anything from your function?
What is the webpage to load if you do get success? I don't see it defined anywhere.
You may want to go back and re-read that section of this homework assignment (???).