新开始学习MVC3 做了个项目，总是抱错，不知道有关问题在那，请

新开始学习MVC3 做了个项目，总是抱错，不知道问题在那，请高手指点
先将源代码贴上，UserInfo 模型层
using System;
using System.Data.Entity;
namespace Mvc.Models
{
  public class UserInfo
  {
  public int UserID { get; set; }
  public string UserName { get; set; }
  public bool UserSex { get; set; }
  public DateTime UserDate { get; set; }
  }
  public class UserDBcontext : DbContext {
   
  public DbSet<UserInfo> DbTest { get; set; }
  }

}

控制层
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using Mvc.Models;
namespace Mvc.Controllers
{
  public class UserInfoController : Controller
  {
  //
  // GET: /Use/

  UserDBcontext us = new UserDBcontext();

   
  public ActionResult Index()
  {
   
  var skk = from m in us.DbTest where m.UserID < 100 select m;
  return View(skk.ToList());
   
  }

  }
}
 wiew 显示层

@model IEnumerable<Mvc.Models.UserInfo>

@{
  ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
  @Html.ActionLink("Create New", "Create")
</p>
<table>
  <tr>
  <th>
  UserID
  </th>
  <th>
  UserName
  </th>
  <th>
  UserSex
  </th>
  <th>
  UserDate
  </th>
  <th></th>
  </tr>

@foreach (var item in Model) {
  <tr>
  <td>
  @Html.DisplayFor(modelItem => item.UserID)
  </td>
  <td>
  @Html.DisplayFor(modelItem => item.UserName)
  </td>
  <td>
  @Html.DisplayFor(modelItem => item.UserSex)
  </td>
  <td>
  @Html.DisplayFor(modelItem => item.UserDate)
  </td>
  <td>
  </td>
  </tr>
}

</table>



web.config 文件

<configuration>
  <connectionStrings>
<add name="DbTest"
  connectionString=" Data Source=.;
Initial Catalog=DbTest;Persist Security Info=True;
User ID=sa;Password=1s@u@n* "
  providerName="System.Data.SqlClient" />

  </connectionStrings>

  <appSettings>
  <add key="webpages:Version" value="1.0.0.0"/>
  <add key="ClientValidationEnabled" value="true"/>
  <add key="UnobtrusiveJavaScriptEnabled" value="true"/>
  </appSettings>

  <system.web>
  <compilation debug="true" targetFramework="4.0">
  <assemblies>
  <add assembly="System.Web.Abstractions, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
  <add assembly="System.Web.Helpers, Version=1.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />
  <add assembly="System.Web.Routing, Version=4.0.0.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35" />