public string Save(Product product)
        {
            bool isProductExist = CheckProduct(product);

            if (product.Name.Length > 0)
            {
                if (isProductExist)
                {
                    return("This item Name is already exist! Please use another Name");
                }
                else
                {
                    int rowAffected = productGateway.InsertProduct(product);

                    if (rowAffected > 0)
                    {
                        return("Saved Successfully!");
                    }
                    else
                    {
                        return("Save Failed!");
                    }
                }
            }
            else
            {
                return("Invalid Category Name! it can't be null.");
            }
        }