Preventing form resubmission

Question

Page one contains an HTML form. Page two - the code that handles the submitted data.

The form in page one gets submitted. The browser gets redirected to page two. P

Answer 1

Well I found nobody mentioned this trick.

Without redirection, you can still prevent the form confirmation when refresh.

By default, form code is like this:

now, change it to

You will see the magic.

I guess its because browsers won't trigger the confirmation alert popup if it gets a GET method (query string) in the url.