// try it at: http://kanzie.com/bgc/rpc.php?mode=addCart&productid=14,15,16,14,14,15,14 if ($_GET['mode'] == "addCart") { if (isset($_GET['productid'])) { $products = explode(",",$_GET['productid']); var_dump($products); if (isset($products)) { if (!isset($_SESSION['cart'])) { $_SESSION['cart'] = array(); echo "<br />SESSION Cart not set, setting it <br />"; } foreach ($products as $key) { if (array_key_exists($key,$_SESSION['cart'])) { $_SESSION['cart'][$key]++; echo "Key " . $key . " exists, incrementing value, value now " . $_SESSION['cart'][$key] . "<br />"; } else { $_SESSION['cart'] = array($key => 1); echo "no previous key for " . $key .", setting value 1<br />"; } } // for every productid in productid-POST } // no products set in the products= POST } // productid-POST is not set } // mode is not "addCart" echo("<br /><br />"); print_r(array_values($_SESSION['cart']));