IE6 Resubmitting form with back button

[btothap]

I've run into a wall and i've been unable to google my way out of it and any help would be greatly appreciated.

basically I have a form with two dropdown boxes that are populated from a mysql database. The choice from the first box populates the second box via javascript.

When the form is submitted, a script decides which page you need to be redirected to based on another database call. The form is currently posting to self, but initially the redirect script was in its own file.

All of this works fine until the user hits the back button from the landing page. IE6 is including $_POST['submit'] when the back button is pressed and the form immediately returns to the referring page, effectively killing the back button.

This only seems to be an issue on ie6 as safari and firefox work fine.

If anyone has any ideas about a way to keep the form from submitting when the back button is pressed I'd be greatful to hear them.

-sA

[rehfeld]

before redirecting them, you could set a session var or cookie to indicate that they have already been redirected. check for that, if its not there, redirect. if its there, dont redirect.

[btothap]

Thanks for your help, Quick question though,
If i set a session variable or cookie, won't that break the submit for subsiquent visits?

[rehfeld]

it could. if you dont want that to happen you could set a value to check against instead of just a flag.

for example, in the form

<input type="hidden" name="submission_id" value="<?php echo uniqid(); ?>">

then when receiving it

session_start();
if ($_SESSION['submission_id'] != $_POST['submission_id']) {
    $_SESSION['submission_id'] = $_POST['submission_id'];  // note the new one
    // redirect
} else {
    // dont redirect
}