PHP Problem

Ok, so on I site I'm currently working on, it has a shopping cart system that utilizes the session to hold what the user is ordering. Here is my problem: when I try and execute the code to remove a thing from the cart, it takes like a minute to load the page, and when it does, it's not the GUI that it should be, but instead a blank page with absolutely no HTML at all. When I press the "back" button, I see it has done what it should have, but I just don't know what's wrong. The code in question is below... Any help?

(oh, and please, don't comment on the poor formatting/optimization of the code unless it's the cause of my problem... Right now I'm working just to get it completed; not to make it look pretty)

PHP:

case 'remove':
            if($_GET['ext'] == "all") {
                foreach($_SESSION['sell_items'] as $keyy => $vall) {
                    unset($_SESSION['sell_items'][$keyy]);
                }
                $output = '
<script language="javascript">

alert("All items successfully removed from shopping cart.");
location.href="checkout.php?do=viewcart";

</script>';
            } else {
                foreach($_SESSION['sell_items'] as $key => $val) {
                    if($key == $_POST['item_id']) {
                        $r_key = $key;
                        break;
                    } else {
                        $r_key = 'blahblah';
                    }
                }
            
                if($r_key === 'blahblah') {                
                    $output = '
<center>
 There was an error in your request. Please try again. If problem persists, please contact an administrator.
</center>';
                } else {
                    unset($_SESSION['sell_items'][$r_key]);
                    
                    $x = 0;
                    foreach($_SESSION['sell_items'] as $s_key => $s_val) {
                        $value = $s_val;
                        $ar_key = $s_key;
                        unset($_SESSION['sell_items'][$ar_key]);
                        $_SESSION['sell_items'][$x] = $value;
                        $x++;
                    }
                    
                    $output = '
<script language="javascript">

alert("Item successfully removed from shopping cart.");
location.href="checkout.php?do=viewcart";

</script>';
                }
            }
            break;

 

Normally would never do this, but this is rather important, so... *bump*

 

Sadly i am rather new to PHP coding but if you want some help then PHP Freaks forum is the place to go if it is an emergency

My own site runs PHP forum aswell as bridged into a CMS. I need help al the time.

Good luck.