function loginFun() 
{
    var userName = document.getElementById("TxtUserName").value;
    var userSN = document.getElementById("TxtPassword").value;
    if (userName == "") 
    {
        alert("请输入账号");
    }
    else if (userSN == "") 
    {
        alert("请输入密码");
    }
     else 
    {
        var hRq = createHttpRequest(); //创建ajax对象
        hRq.open("POST", "UserLogin.ashx?user=" + userName + "&sn=" + userSN, false);
        hRq.send();

    }
}

 public class UserLogin1 : IHttpHandler
    {

        public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "text/plain";
            string userName = context.Request["user"];
            string userSn = context.Request["sn"];

            string connctionStr = ConfigurationManager.AppSettings["DbConnectionString"];
            try
            {
                using (SqlConnection sqlConn = new SqlConnection(connctionStr))
                {
                    sqlConn.Open();
                    SqlCommand sqlCmd = new SqlCommand("select top 1 * from users where userName like '" + userName + "'",sqlConn);
                    SqlDataReader sqlDR = sqlCmd.ExecuteReader();

                    if (sqlDR.Read())
                    {
                        string name = sqlDR["userName"].ToString();
                        string sn = sqlDR["userSN"].ToString();
                        string userRight = sqlDR["Edit_right"].ToString();

                        if (name == userName && userSn == sn)
                        {
                            if (userRight == "false")
                            {
                                
                            }
                            else
                            {

                                context.Response.Redirect("Default.aspx",false);
                            }
                        }

                        else
                        {
                            context.Response.Write("用户名或密码错误！");
                        }
                    }
                    sqlDR.Close();
                }
            }
            catch (Exception e)
            {
                
                context.Response.Write(e.Message);
            }
           
        }

        public bool IsReusable
        {
            get
            {
                return false;
            }
        }
    }
}