protected void Update_Click(object sender, EventArgs e)
        {
            if (IsValid)
            {
                ProductItem currentProduct = Session["Product"] as ProductItem;

                currentProduct.productDescription = txtProductDescription.Text;
                if (fullImage.HasFile)
                {
                    currentProduct.productImage = fullImage.FileName;
                }

                uploadImageFile(fullImage);

                currentProduct.productPrice = Convert.ToDouble(txtPrice.Text);


                Session["Product"] = currentProduct;

                ProductItem.updateProduct(currentProduct);

                Session.Remove("Product");

                Response.Redirect("~/UL/AdminProductManagement");
            }
        }