สั่งซื้อสินค้าไปแล้วหากมีการกดสั่งซื้อรายการเดิมอีกให้ทำการบวกจำนวนเพิ่มรายการนั้นในตะกร้าสินค้า

<?php
if (!isset($_SESSION['SHOPPING_CART'])){ $_SESSION['SHOPPING_CART'] = array(); }

if (isset($_POST['productname']) && isset($_POST['productprice']) && isset($_POST['qty'])&& isset($_POST['pid'])){
	
	$ITEM = array(	
		'name' => $_POST['productname'],	
		'pid' => $_POST['pid'],
		'price' => $_POST['productprice'], 
		'qty' => $_POST['qty']		
		);
	$_SESSION['SHOPPING_CART'][] =  $ITEM;
	echo"<meta http-equiv=\"refresh\" content=\"0;url=index.php?rep=basket\">";
}
else if (isset($_GET['remove'])){
	unset($_SESSION['SHOPPING_CART'][$_GET['remove']]);
	//echo"<meta http-equiv=\"refresh\" content=\"0;url=index.php?rep=basket\">";
}
else if (isset($_GET['empty'])){
	session_destroy();
	//echo"<meta http-equiv=\"refresh\" content=\"0;url=index.php?rep=basket\">";
}
else if (isset($_POST['update'])) {

	foreach ($_POST['items_qty'] as $itemID => $qty) {
		if ($qty == 0) {
			unset($_SESSION['SHOPPING_CART'][$itemID]);
		}
		else if($qty >= 1) {
			$_SESSION['SHOPPING_CART'][$itemID]['qty'] = $qty;
		}
	}
	//echo"<meta http-equiv=\"refresh\" content=\"0;url=index.php?rep=basket\">";
} 

?>