cart is empty after add to cart (in private window working fine)

Question

cart is empty after add to cart (in private window working fine) magento 1.9.2 programmatically.

i've used

$cart = Mage::getSingleton('checkout/cart'); //getModel
$cart->init(); 
$cart->addProduct($product, $qty);  // update session
$session->setCartWasUpdated(true);
$cart->save();
$quote->setIsActive(1);
$quote->collectTotals()->save();
Mage::getSingleton('checkout/session')->setCartWasUpdated(true);