function changeItem()
{
$itemId = JRequest::getVar('itemId');
$value = JRequest::getVar('value', 1, 'method', 'int');
if (empty($value)) {
$value = 1;
}
$buy4friend = JRequest::getVar('buy4friend', 0, 'method', 'int');
//-----------------------------
// get max purchase per user allowed and check if the update qty is > or not
$maxBuyQtyOfDeal = EnmasseHelper::getMaxBuyQtyOfDeal($itemId);
if ($maxBuyQtyOfDeal >= 0 && $value > $maxBuyQtyOfDeal) {
$msg = JText::_("ITEM_UPDATE_GREATER_THAN_MAX");
JFactory::getApplication()->redirect("index.php?option=com_enmasse&controller=shopping&task=checkout", $msg);
}
$cart = unserialize(JFactory::getSession()->get('cart'));
CartHelper::checkCart($cart);
$cart->changeItem($itemId, $value);
JFactory::getSession()->set('cart', serialize($cart));
$msg = JText::_("ITEM_UPDATE_MSG");
$link = JRoute::_("index.php?option=com_enmasse&controller=shopping&task=checkout&buy4friend={$buy4friend}", false);
JFactory::getApplication()->redirect($link, $msg);
}
