sql查询出错

Console.WriteLine("请输入用户名:");
           string UserNaem=Console.ReadLine();
            Console.WriteLine("请输入密码：");
           string PassWord=Console.ReadLine();
            using(SqlConnection conn=new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=F:\aspnet\数据库连接测试\数据库连接测试\B_User.mdf;Integrated Security=True;User Instance=True"))
            {
                conn.Open();
                using(SqlCommand cmd=conn.CreateCommand())
                {
                   cmd.CommandText = "select * from T_User where UserName='"+UserNaem+"'";
                   using(SqlDataReader reader=cmd.ExecuteReader())
                   {
                       if (reader.Read())
                       {
                           //用户名存在
                           string dbpassword = reader.GetString(reader.GetOrdinal("PassWord"));
                           PassWord = Convert.ToString(PassWord);
                           if (PassWord == dbpassword)
                           {
                               Console.WriteLine("登陆成功！");
                           }
                           else
                           {
                               Console.WriteLine("密码错误，登陆失败！");
                           }
                       }
                       else
                       {
                           Console.WriteLine("用户名不存在！");
                       }
                   }
                        Console.WriteLine("查询成功！"); 
                 
                
                }
                conn.Close();
                Console.ReadKey();
            }以上代码， if (PassWord == dbpassword)
                           {
                               Console.WriteLine("登陆成功！");
                           }
这句，就算我输入正常的用户名，密码，打印出的变量也正确，比较结果都是FASH！显示为： Console.WriteLine("密码错误，登陆失败！");
这句。
想知道原因！