public List <SelectListItem> GetAllCourseSlItems()
        {
            var courses = _trainerManager.GetAllCourse();
            var slItems = new List <SelectListItem>();

            foreach (var course in courses)
            {
                var sli = new SelectListItem();
                sli.Text  = course.Name + " - " + course.Code;
                sli.Value = course.Id.ToString();
                slItems.Add(sli);
            }
            return(slItems);
        }