ajax post方法

            $.post("../ajax/Login.ashx",
               {
                   UserName: username,
                   Pwd: pwd,
                   CheckCode: chkcode
               },
               function (data, status) {
                   if (data == "验证码不正确") {
                       alert("验证码不正确！");
                   }else if (data=="登录成功") {
                       alert("登录成功!");
                   }else {
                       alert("用户名或密码错误!");
                   }
               });

            string username = context.Request.Form["UserName"].ToString();
            string pwd = context.Request.Form["Pwd"].ToString();
            string cm = context.Session["CheckCode"].ToString();

.....


            using (cmd = new SqlCommand(strsql, con))
            {
                using (read = cmd.ExecuteReader())
                {
                    if (!flag)
                    {
                        context.Response.Write("验证码不正确");
                        //drow.Add("验证码", "验证码不正确！");
                        //return;
                    }
                    else if (read.Read())
                    {
                        context.Response.Write("登录成功");
                        //drow.Add("登录成功", "登录成功！");
                    }
                    else
                    {
                        context.Response.Write("用户名或密码错误");
                        //drow.Add("登录失败", "用户名或密码错误！");
                    }
                }

            }