/// <summary>
 /// Executes the add product command
 /// </summary>
 private void AddNewProductExecute()
 {
     try
     {
         AddProduct addProduct = new AddProduct();
         addProduct.ShowDialog();
         if ((addProduct.DataContext as AddProductViewModel).IsUpdateProduct == true)
         {
             UnstoredProduct = service.GetAllProducts().Where(product => product.Stored == false).ToList();
             service.Notify("Added " + UnstoredProduct.LastOrDefault().ProductName + ", code " + UnstoredProduct.LastOrDefault().ProductCode
                            + ", quantity " + UnstoredProduct.LastOrDefault().Quantity + ", price " + UnstoredProduct.LastOrDefault().Price);
         }
         Priview();
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.ToString());
     }
 }
        /// <summary>
        /// Check if the product table will be shown or not depending if its empty or not
        /// </summary>
        public void Priview()
        {
            if (UnstoredProduct.Any())
            {
                UnstoredProductExists = Visibility.Visible;
            }
            else
            {
                UnstoredProductExists = Visibility.Collapsed;
            }

            if (StoredProduct.Any())
            {
                StoredProductExists = Visibility.Visible;
            }
            else
            {
                StoredProductExists = Visibility.Collapsed;
            }
        }