Getting Null in var obj why ? How to solve This ??

public ActionResult Login(UserResgitartion objUser)

{

if (ModelState.IsValid)

{

using (MyDatabaseEntities Db = new MyDatabaseEntities())

{

var obj = Db.UserResgitartions.Where(a => a.UserName.Equals(objUser.UserName) && a.Password.Equals(objUser.Password)).SingleOrDefault();

if(obj != null)

{

Session["UserID"]= obj.UserID.ToString();

Session["USERNAME"] = obj.UserName.ToString();

if (objUser.UserName == "Admin" && objUser.Password == "admin")

{

return View("AdminDashBoard");

}

else

{

return View ("UserDashBoard");

}

// return RedirectToAction("UserDashBoard");

}

}

}

return View(objUser);

}