PHP文档在表单帖子上过期

Question

I have page 1 with form (POST) that posts to page 2 that if form POSTed shows result if form is not POSTed and page 2 open it shows other content based on PHP if. Page 2 has link to page 3 and when i post form from page 1 -> page 2 and go to page 3 via link then i click back and get "Document expired"

Someone told me its n normal, however why's that happening? I assumed if PHP check's POST variable not exists and gives different content to page it should how fine.

Is there any way's to make it work or its coded into browser to behave like that?

Edit Answer: <?php session_cache_limiter('private_no_expire'); ... ?> fixed it

Answer 1

In your form processing script (Page 2, I think) you should redirect once you've processed the data. That way the user never sees that error.

Example:

if (isset($_POST['submit'])) {
    // save something to database
    header('Location: http://www.example.com/page2');
    exit;
}

// other content