Save Custome Attribute

$product->setData(‘vendor’,$VendorId[0][‘vendor_name’]);
$product->getResource()->saveAttribute($product, ‘vendor’);

Get Used discount amount on cart

$quote = Mage::getSingleton(‘checkout/session’)->getQuote();
foreach ($quote->getAllItems() as $item){
echo $item->getDiscountAmount().'<br>’;
echo(“<script>console.log(‘PHP: “.json_encode($item->getData()).”‘);</script>”);
}