public ActionResult RemoveFromCart(int cartId, int productId)
{
List <CartViewModel> cartViewModels = Session["CartItems"] as List <CartViewModel>;
Session["CartItems"] = cartServices.RemoveFromCart(cartViewModels, cartId, productId);
Session["CartCounter"] = (Session["CartItems"] as List <CartViewModel>).Count;
return(RedirectToAction("ShowCart"));
}