public void UpdateTest(Test t)
        {
            Test test_t = new Test();

            try
            {
                XElement testElement = (from stu in XMLDS.DrivingTests.Elements()
                                        where (stu.Element("id").Value) == t.TestNumber
                                        select stu).FirstOrDefault();

                string temp = "";
                foreach (string item in t.TesterNotes)
                {
                    temp += "." + item;
                }
                testElement.Element("NOTE").Value = temp;
                testElement.Element("parameters").Element("Keep_Distance").Value         = t.TestParameters[0].ToString();
                testElement.Element("parameters").Element("Reverse_Parking").Value       = t.TestParameters[1].ToString();
                testElement.Element("parameters").Element("Looking_in_the_Mirors").Value = t.TestParameters[2].ToString();
                testElement.Element("parameters").Element("Signals").Value        = t.TestParameters[3].ToString();
                testElement.Element("parameters").Element("Wheel_handling").Value = t.TestParameters[4].ToString();
                testElement.Element("parameters").Element("Priority_Rules").Value = t.TestParameters[5].ToString();
                testElement.Element("Pass").Value = t.IsPass.ToString();



                XMLDS.SaveDrivingtests();
            }
            catch
            {
                throw new Exception("  test Not exist");
            }
        }
        public void AddTest(Test t)
        {
            t.TestNumber = get_num_test().ToString("00000000");


            //Build a new test Eelement file
            XElement id         = new XElement("id", t.TestNumber);
            XElement ID_TESTER  = new XElement("ID_TESTER", t.TesterId);
            XElement ID_TRAINEE = new XElement("ID_TRAINEE", t.TraineeId);
            XElement DATE       = new XElement("DATE", t.TestDate);
            XElement City       = new XElement("City", t.TestAddress.city);
            XElement Street     = new XElement("Street", t.TestAddress.streetName);
            XElement Number     = new XElement("Number", t.TestAddress.houseNumber);
            XElement Address    = new XElement("Address", City, Street, Number);
            XElement IsUpdate   = new XElement("IsUpdate", t.ISUpdated);

            XElement Keep_Distance         = new XElement("Keep_Distance", false.ToString());
            XElement Reverse_Parking       = new XElement("Reverse_Parking", false.ToString());
            XElement Looking_in_the_Mirors = new XElement("Looking_in_the_Mirors", false.ToString());
            XElement Signals        = new XElement("Signals", false.ToString());
            XElement Wheel_handling = new XElement("Wheel_handling", false.ToString());
            XElement Priority_Rules = new XElement("Priority_Rules", false.ToString());

            XElement parameters = new XElement("parameters", Keep_Distance, Reverse_Parking, Looking_in_the_Mirors, Signals, Wheel_handling, Priority_Rules);
            XElement Pass       = new XElement("Pass", t.IsPass);

            XElement NOTE = new XElement("NOTE", t.TesterNotes);

            XMLDS.DrivingTests.Add(new XElement("test", id, ID_TESTER, ID_TRAINEE, DATE, Address, Pass, NOTE, parameters, IsUpdate));
            XMLDS.SaveDrivingtests();
        }