cannot save changes of courses if remove in edit httppost

Question

Problem

when remove course then click submit not save changes although

it removed from client side by jquery

Details 

in edit view for every employee i need to do changes by remove or add new courses for employee

if i add new courses then click submit button it save what i do

but if i remove course from courses then click submit it will not save courses i removed

so that i need to check what is wrong in my code

my code working without any problem  but only have problem

i cannot save courses removed in database in employeecourse table when click submit 

employeecourse table have Id,EmployeeId,CourseId

jquery remove client side attached with my question 

code 

my code as following 

 [HttpPost]
        public ActionResult Edit(EditEmployeeVm model)
        {
            var emp = db.Employees.FirstOrDefault(f => f.Id == model.Id);
            foreach (var couseid in model.CourseIds)
            {
                db.EmployeeCourses.Add(new EmployeeCourse { CourseId = couseid, EmployeeId = emp.Id });
                db.SaveChanges();
            }

            return View();
my(custom model) view model using for that
 public class EditEmployeeVm
    {
        public int Id { set; get; }
        public List<SelectListItem> Courses { get; set; }
        public int[] CourseIds { set; get; }
        public List<CourseVm> ExistingCourses { set; get; }
    }
    public class CourseVm
    {
        public int Id { set; get; }
        public string Name { set; get; }
    }
}

 to show what i need clearly see image below