Sessions

[Anon]

I am working on a shopping cart site and am experiencing intermittent problems with the shopping cart not adding items -sometimes you can add items, other times it just replaces the previous item with the new.

The error message I get is below:

Warning: Cannot send session cookie - headers already sent by (output started at /usr/home/b/e/beats/public_html/show_cart.php:2) in /usr/home/b/e/beats/public_html/show_cart.php on line 5

Warning: Cannot send session cache limiter - headers already sent (output started at /usr/home/b/e/beats/public_html/show_cart.php:2) in /usr/home/b/e/beats/public_html/show_cart.php on line 5

The relevant section of code it refers to is below:

session_start();

if($new)
{
//new item selected
if(!session_is_registered("cart"))
{
$cart = array();
session_register("cart");
$items = 0;
session_register("items");
$total_price = "0.00";

session_register("total_price");
}
if($cart[$new])
$cart[$new]++;
else
$cart[$new] = 1;
$total_price = calculate_price($cart);
$items = calculate_items($cart);

}

Any ideas as to what may be the problem?Any help/pointers much appreciated.

regards,

Robin Porter

[Anon]

The headers already sent message usually crops up because you have a space outside of your <?php ?> tags in one of your scripts. When PHP encounters what it considers HTML code (anything not inside the php tags) it sends it to Apache and apache sends it out, if it's the first thing Apache has to send out it sends the headers also. This causes your sessions to break because they need to send cookie information.

So I'd start by checking all scripts that are being run (included ones also) to makes sure they aren't sending anything to the browser until after your session_start() call.