I have a question how to add input fields values with same name into the database using entity framework? Below is my code, - asp.net-mvc

Question

This is my HomeWithIndentityController
namespace MVC.CRUDDynamicFormTest.Controllers
{
public class HomeWithIndentityController : Controller
{
// GET: HomeWithIndentity
public ActionResult WithIndex()
{
return View();
}
public ActionResult GetData()
{
using (DynamicCRUDDatabase2Entities db = new DynamicCRUDDatabase2Entities())
{
List<DynamicCRUDTable2> dynamicCRUDTable2s = db.DynamicCRUDTable2.ToList<DynamicCRUDTable2>();
return Json(new { data = dynamicCRUDTable2s }, JsonRequestBehavior.AllowGet);
}
}
[HttpGet]
public ActionResult Add(int id = 0)
{
return View(new DynamicCRUDTable2());
}
[HttpPost]
public ActionResult Add(DynamicCRUDTable2 obj)
{
using (DynamicCRUDDatabase2Entities db = new DynamicCRUDDatabase2Entities())
{
db.DynamicCRUDTable2.Add(obj);
db.SaveChanges();
return Json(new { succces = true, message = "saved Successfully" }, JsonRequestBehavior.AllowGet);
//return RedirectToAction("Index", "Home");
}
}
}
}
this is my entity model class
public partial class DynamicCRUDTable2
{
public int Id { get; set; }
public string FirstName { get; set; }
}
This my View
<form action="~/HomeWithIndentity/Add" method="POST" onsubmit="return Submitform(this)">
<input data-val="true" id="Id" name="Id" type="hidden" />
<label>First Name</label>
<input type="text" name="FirstName[]" class="form-control" />
<input type="text" name="FirstName[]" class="form-control" />
<br />
<br />
<div>
<input type="submit" value="Submit" class="btn btn-success" />
<input type="reset" value="Reset" class="btn btn-danger" />
<a class="btn btn-danger" href="~/Home/Index">Cancel</a>
</div>
</form>
In the above view i want to add the firstname input field values to the Database dynamicallly.but it does not working can you let me know why?What errors i have done.
does anyone know how to do that?