protected void GetOverallVATPercentage()
        {
            ProductPriceBLL productPrice = new ProductPriceBLL();

            try
            {
                DataTable dt = productPrice.GetOverallProductVAT();

                vatTextBox.Text = dt.Rows[0][0].ToString();
                vatTextBox.ReadOnly = true;
            }
            catch (Exception ex)
            {
                string message = ex.Message;
                if (ex.InnerException != null) { message += " --> " + ex.InnerException.Message; }
                MyAlertBox("ErrorAlert(\"" + ex.GetType() + "\", \"" + message + "\", \"\");");
            }
            finally
            {
                productPrice = null;
                MyAlertBox("MyOverlayStop();");
            }
        }