Parameter has no default value

string updateSql = "UPDATE [RateCenters] " + "SET [RateCenterName] = @RateCenterName, [Province]= @Province, [QuantityThreshold] =@QuantityThreshold  " + "WHERE [RateCenterID]=@RateCenterID";


    string ratecenterID;


        protected void GridView1_RowUpdating(object sender, GridViewUpdateEventArgs e)
        {                    
            GridViewRow row = (GridViewRow)GridView1.Rows[e.RowIndex];
            DropDownList ddl = (DropDownList)row.FindControl("DropDownList2");
            TextBox rateCenterName = (TextBox)row.FindControl("TextBox1");
            TextBox quantityThreshold = (TextBox)row.FindControl("TextBox2");


            OleDbConnection conn = new OleDbConnection(ConfigurationManager.ConnectionStrings["DBConnection"].ToString());
            OleDbCommand cmd = null;


            try
            {
                conn.Open();
                cmd = new OleDbCommand(updateSql, conn);
                cmd.Parameters.Add("@RateCenterName", OleDbType.VarChar).Value = rateCenterName.Text;
                cmd.Parameters.Add("@Province", OleDbType.VarChar).Value = ddl.SelectedValue;
                cmd.Parameters.Add("@QuantityThreshold", OleDbType.VarChar).Value = quantityThreshold.Text;


                cmd.Connection = conn;
                cmd.ExecuteNonQuery();

                GridView1.EditIndex = -1;
                GridView1.DataBind();
            }
            catch (OleDbException ex)
            {
                throw (ex);
            }
            finally
            {
                cmd.Dispose();
                conn.Close();
                conn.Dispose();
            }
        }