How can only Password field is getting cleared after clicking on login button

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;

namespace MVCRegistration.Controllers
{
    public class HomeController : Controller
    {
        [AllowAnonymous]
        public ActionResult Index()
        {
            ViewBag.Message = "Modify this template to jump-start your ASP.NET MVC application.";

            return View();
        }

        public ActionResult About()
        {
            ViewBag.Message = "Your app description page.";

            return View();
        }

        public ActionResult Contact()
        {
            ViewBag.Message = "Your contact page.";

            return View();
        }
        public ActionResult Login()
        {
            return View();
        }
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Login(User u)
        {
            if(ModelState.IsValid)
            {
                using (MyDatabaseEntities dc=new MyDatabaseEntities())
                {
                    var v=dc.Users.Where(a=>a.UserName.Equals(u.UserName) && a.Password.Equals(u.Password)).FirstOrDefault();
                    if(v !=null)
                    {
                        Session["LogedUserId"] = v.UserId.ToString();
                        Session["LogedUserFullName"] = v.FullName.ToString();
                        return RedirectToAction("AfterLogin");
                    }
                }

            }
            return View(u);

        }
        public ActionResult AfterLogin()
        {
            if(Session["LogedUserId"]!=null)
            {
                return View();
            }
            else
            {
                return RedirectToAction("Index");
            }
            
        }

    }
}