Remove question mark added to url using form 'get' method

Question

I am using a form and the 'get' method to offer users a return option to an unknown url that they came from within my site, as per the code below. I prefer this to just the browsers back button and it works without javascript.

The problem I am having is that some browsers (chrome, safari, there may be others) are adding a question mark to the end of the url they are referred back to. I don't want this for seo reasons.

My question is either:

1) Can I prevent the question mark within my php code somehow; or

2) Please could somebody show me how to redirect the url using htaccess, I potentially have urls that could end:-

.html?

.htm?

.php?

/?

Thanks in advance.

<?php
if (isset ($_SERVER['HTTP_REFERER']) ) {
$url = htmlspecialchars($_SERVER['HTTP_REFERER']);
echo '<br /><form action="' . $url . '" method="get">
<div id="submit"><input type="submit"  value="Return to previous page" /></div>
</form>';
}
?>

Answer 1

The ? probably gets added because you're doing a GET request from a form.

Why not do something like:

<input type="button" onclick='document.location.href=<?php echo json_encode($url);?>'>;

Answer 2

use POST method instead of GET