Friends
I think this is due to some problem in my stored procedure.
Please, please take a look and tell me what is it that I am doing wrong. I have a product page from which users can select color, size, and width from three drop down lists. When they click "Add To Cart", the following routine fires:

private void processCommand(object source, System.Web.UI.WebControls.DataListCommandEventArgs e)
        {
            if (e.CommandName.Equals("AddToCart"))

            {
                DropDownList ddlColor = (DropDownList)e.Item.FindControl("ddlColor");
                DropDownList ddlSize = (DropDownList)e.Item.FindControl("ddlSize");
                DropDownList ddlWidth = (DropDownList)e.Item.FindControl("ddlWidth");
                Server.Transfer("PPAddToCart.aspx?ProductID=" + e.CommandArgument.ToString()+ "&shoecolor=" + ddlColor.SelectedValue.ToString() + "&shoesize=" + ddlSize.SelectedValue.ToString() + "&shoewidth=" + ddlWidth.SelectedValue.ToString());
            }

        }

As you can see, this is transferred to PPAddToCart.aspx which on Page Load does the following routine:

public PPAddToCart()
        {
            Page.Init += new System.EventHandler(Page_Init);
        }


        private void Page_Load(object sender, System.EventArgs e)
        {
            // Put user code to initialize the page here

            if (Request.Params["ProductID"] != null)
            {
                perrysplace.ppShoppingCartDB cart = new ppShoppingCartDB();

                String CartId = cart.GetShoppingCartId();
                String shoecolor = Request.QueryString["shoecolor"];
                String shoesize = Request.QueryString["shoesize"];
                String shoewidth = Request.QueryString["shoewidth"];





                cart.AddItem(CartId, Int32.Parse(Request.Params["ProductID"]), 1, shoecolor, shoesize, shoewidth);
            }
            Response.Redirect("PPShoppingCart.aspx");
        }

        private void Page_Init(object sender, EventArgs e)
        {
            InitializeComponent();
        }


Here is the SPROC that performs the AddItem method, following which is the method itself.


CREATE Procedure PPShoppingCartAddItem
(
    @CartID nvarchar(50),
    @ProductID int,
    @Quantity int,
    @Color nvarchar(50) = null,
    @ShoeSize nvarchar(50) = null,
    @Width nvarchar(50) = null
)
As

IF LEN(RTRIM(LTRIM(@Color))) = 0 SELECT @Color = null
IF LEN(RTRIM(LTRIM(@ShoeSize))) = 0 SELECT @ShoeSize = null
IF LEN(RTRIM(LTRIM(@Width))) = 0 SELECT @Width = null

DECLARE @CountItems int

SELECT
    @CountItems = Count(ProductID)
FROM
    PPShoppingCart
WHERE
    ProductID = @ProductID
  AND
    CartID = @CartID

IF @CountItems > 0 /* There are items - update the current quantity */

    UPDATE
        PPShoppingCart
    SET
        Quantity = (@Quantity + PPShoppingCart.Quantity)
    WHERE
        ProductID = @ProductID
      AND
        CartID = @CartID

ELSE /* New entry for this Cart. Add a new record */





    INSERT INTO PPShoppingCart
    (
        CartID,
        Quantity,
        ProductID,
    Color,
    ShoeSize,
    Width

    )
    VALUES
    (
        @CartID,
        @Quantity,
        @ProductID,
    @Color,
    @ShoeSize,
    @Width

    )
GO


Here is the AddItem method:

public void AddItem(string cartID, int productID, int quantity, string color, string size, string width)
        {
            //This method add items to shopping cart. Important method!!
            SqlConnection cnCart = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"]);
            SqlCommand cmdSelect = new SqlCommand("PPShoppingCartAddItem", cnCart);

            cmdSelect.CommandType = CommandType.StoredProcedure;

            SqlParameter parameterProductID = new SqlParameter("@ProductID", SqlDbType.Int, 4);
            parameterProductID.Value = productID;
            cmdSelect.Parameters.Add(parameterProductID);

            SqlParameter parameterCartID = new SqlParameter("@CartID", SqlDbType.NVarChar, 50);
            parameterCartID.Value = cartID;
            cmdSelect.Parameters.Add(parameterCartID);

            SqlParameter parameterQuantity = new SqlParameter("@Quantity", SqlDbType.Int, 4);
            parameterQuantity.Value = quantity;
            cmdSelect.Parameters.Add(parameterQuantity);

            SqlParameter parameterColor = new SqlParameter("@Color", SqlDbType.NVarChar, 50);
            parameterQuantity.Value = color;
            cmdSelect.Parameters.Add(parameterColor);

            SqlParameter parameterShoeSize = new SqlParameter("@ShoeSize", SqlDbType.NVarChar, 50);
            parameterQuantity.Value = size;
            cmdSelect.Parameters.Add(parameterShoeSize);

            SqlParameter parameterWidth = new SqlParameter("@Width", SqlDbType.NVarChar, 50);
            parameterQuantity.Value = width;
            cmdSelect.Parameters.Add(parameterWidth);

            cnCart.Open();
            cmdSelect.ExecuteNonQuery();
            cnCart.Close();
        }


The agony is that I had all this going very well about a week ago and then I formatted my harddrive without making any copies of the application.
Please, please take a look and tell me what is it that I am doing wrong. Thanks very much.

I have got the mistake guys. Sorry to have bothered you. There were a bunch of typos in my class methods. Apologies.