I'm not sure if i get the point but, for both question, you can have your form and process script in same file so you'll have the same code from the form file after the submittion.
You can also, after processing, in your registration.php file, add this next code so it will send you to the page you want:
Code: Select all
You can also make this call in the background using xmlhttprequest and nothing will change/move in the form file.
Of course, this all really depends on what you're trying to do.