public static string SaveChanges(string changes)
    {
        Dictionary <string, string> result = new Dictionary <string, string>()
        {
            { "saved", "" }, { "error", "" }
        };
        bool   saved    = false;
        string errorMsg = string.Empty;

        try
        {
            XmlDocument docChanges = (XmlDocument)JsonConvert.DeserializeXmlNode(changes, "changes");

            saved = RQMT.RQMT_Update(Changes: docChanges); //todo: check for uniqueness
        }
        catch (Exception ex)
        {
            LogUtility.LogException(ex);

            saved    = false;
            errorMsg = ex.Message;
        }

        result["saved"] = saved.ToString();
        result["error"] = errorMsg;

        return(JsonConvert.SerializeObject(result, Newtonsoft.Json.Formatting.None));
    }