Clearing form data

[Tigers!]

After a user presses 'submit' and their form data is sent off the user receives a thank you page.
However if they use the back button the form data is still there. How do we remove the form data after 'submit' is selected?

<form method="post" action="/PetalsandPatches/feedback150508.php"> 
 <label>Name*:</label><input name="name" type="text" size="47" />
 <br /><br />
 <label>Address*:</label><input name="address" type="text" size="47" />
 <br /><br />
 <label>City/Town*:</label><input name="city" type="text" size="47" />
 <br /><br />
 <label>State*:</label><input name="state" type="text" size="47" />
 <br /><br />
 <label>Post code*:</label><input name="postcode" type="text" size="47" />
 <br /><br />
 <label>Country*:</label>
 <select name="country" size="1">
.........................
 </select>
 <br /><br />
 <label>E-mail:</label><input name="email" type="text" size="47" />
 <br /><br />
 <input type="submit" value="Order Catalogue">
</form>

[AutisticCuckoo]

There's no guaranteed way, since the browser may reload the page from its cache.

[Tigers!]

Oh dear. What a pity.

[AutisticCuckoo]

You can try sending a Cache-Control: no-store HTTP header, plus an Expires date in the past, but even that's no guarantee.

[genetrix]

I think you can create session -->
works 100%;

session_start(); //in header
when you submit page :
$_SESSION['formhandler']=1;
on form page put this code :
<?
if(isset($_SESSION['formhandler']))
{
print "form already submitted..\n";
unset($_SESSION['formhandler']);
}else{
//here your html form ;
}

?>

CHEERS !!

Check this :

[C. Ankerstjerne]

That still requires the browser to load the page from the server, rather thant the cache.

[genetrix]

if you object oriented programmer ... do following .. create header class : I use header.class.php
create function in your class :
<?
function clean_headers();
{
header('Expires: Mon, 26 Jul 1997 05:00:00 GMT'); //yo can add this header if you want to set expiration date ...
header('Cache-Control: no-store, no-cache, must-revalidate');
header('Cache-Control: post-check=0, pre-check=0', FALSE);
header('Pragma: no-cache');
}
?>

then simple call to your function in page loaded before your html called ... Play with headers .

It was kinda bump .