ViewModel is not persisting database value

Question

i have populated one of my view with this viewmodel

 

public ActionResult AddStudent(int id)

{

var record = (from x in db.Registers

where (x.RegisterId == id)

select new StudentModel()

{

Batch = x.Batch,

ClassRoll = x.RoleNo,

Department = x.Department,

Name = x.StudentFullName

}).ToList();

return View(record);

}

these values are coming from database and persist on viewmodel to display but the problem is

 

 

[HttpPost]

[ValidateAntiForgeryToken]

public ActionResult AddStudent(StudentModel s)

{

Student stu = new Student();

s.LibraryCardNo = stu.LibraryCardNo;

s.Name = stu.Name;

s.Department = stu.Department;

s.Batch = stu.Batch;

s.ClassRoll = stu.RollNo;

db.Students.Add(stu);

ViewBag.Msg = "Record Inserted";

return View();

}

 

when this viewmodel is sent back to processing t 

 hese values are empty i don't know how to fix this thing.please help me