public static string CallJInt(string expression)
        {
            string _result = "";
            string _expression = expression;

            try
            {
                // execute the expression
                object _returnValue = new JintEngine().Run(_expression);

                if (_returnValue != null)
                {
                    _result = _returnValue.ToString();
                }
            }
            catch (Exception ex)
            {
                _result = "$$ERR:" + ex.Message;
                IGenFormCommonRoutines._processMessages.Add("For expression: " + expression + ", err=" + ex.Message);
            }

            return _result;
        }