function inStock($skus){
        if ($skus->getSize()) {
            $collection = Mage::getModel('catalog/product')
                ->getCollection()
                ->addAttributeToFilter('sku', array('in' => $skus));
            foreach ($collection as $product) {
                $quantity = Mage::getModel('cataloginventory/stock_item')->loadByProduct($product)->getQty();
                if ($quantity < $sku->getRequiredQuantity()) {
                    return false;
                }
            }
        } else {
            return false;
        }
        return true;
    }