private void ValidateCode()
        {
            ClearErrors();
            int ce = Code;

            if ((ce == null))
            {
                AddError("Code", Properties.Resources.Error_Required);
            }
            else if ((XCode.Contains(ce)))
            {
                AddError("Code", Properties.Resources.Error_CodeAlreadyExist);
            }


            else
            {
                if (fcode != Code)
                {
                    MessageBoxResult result = MessageBox.Show("Voulez vous changer le code du cours ?", "Confirmation", MessageBoxButton.YesNo);
                    switch (result)
                    {
                    case MessageBoxResult.Yes:
                        Course.Code = (int)code;

                        App.CurrentCourse = Course;
                        break;

                    case MessageBoxResult.No:
                        break;
                    }
                }
            }
            RaiseErrors();
        }