Jquery의 $.ajax() 메소드 매개변수에 대한 자세한 설명

$(function(){
  $('#send').click(function(){
     $.ajax({
       type: "GET",
       url: "test.json",
       data: {username:$("#username").val(), content:$("#content").val()},
       dataType: "json",
       success: function(data){
             $('#resText').empty();  //清空resText里面的所有内容
             var html = ''; 
             $.each(data, function(commentIndex, comment){
                html += &#39;<p class="comment"><h6>&#39; + comment[&#39;username&#39;]
                     + &#39;:</h6><p class="para"&#39; + comment[&#39;content&#39;]
                     + &#39;</p></p>&#39;;
             });
             $(&#39;#resText&#39;).html(html);
           }
     });
  });
});

 <script type="text/javascript" language="javascript">
    function IbtnEnter_onclick() {
      checklogin();
      return false;
    }
    function checklogin() {
      if ($("#TxtUserName").val() == "") {
        alert("用户名不能为空！");
        $("#TxtUserName").focus();
        return false;
      }
      if ($("#TxtPassword").val() == "") {
        alert("密码不能为空！");
        $("#TxtPassword").focus();
        return false;
      }
      $.ajax({
        type: "POST",
        url: "ajax/Handler.ashx?M=" + Math.random(),
        data: "username=" + $("#TxtUserName").val().toString() + "&pwd=" + $("#TxtPassword").val().toString(),
        success: function (data) {
          if (data == "1") {
            location.href = "index.aspx";
            return true;
          }
          else {
            alert("请确认您输入的用户名或密码输入是否正确！");
            $("#TxtUserName").val("");
            $("#TxtPassword").val("");
            $("#TxtUserName").focus();
            return false;
          }
        }
      })
    }
  </script>

<%@ WebHandler Language="C#" Class="Handler" %>
using System;
using System.Web;
using System.Data.SqlClient;
using System.Web.SessionState;//继承接口IReadOnlySessionState需要引入的命名空间
public class Handler : IHttpHandler, IRequiresSessionState
{
  SqlHelper helper = new SqlHelper();
  public void ProcessRequest(HttpContext context)
  {
    context.Response.ContentType = "text/plain";
    string username = context.Request.Params["username"].ToString().Trim();
    string pwd = context.Request.Params["pwd"].ToString().Trim();
    if (username != "" && pwd != "")
    {
      string sql = @"SELECT * FROM [USER] WHERE USERNAME=&#39;"+username+"&#39; AND PASSWORD=&#39;"+pwd+"&#39; ";
      if (!helper.Exists(sql))
      {
        context.Response.Write("0");
      }
      else
      {
        SqlDataReader reader = helper.ExecuteReader(sql);
        while (reader.Read())
        {
          context.Response.Write("1");
          context.Session["username"] = username.ToString().Trim();
          context.Session["pwd"] = pwd.ToString().Trim();
        }
      }
    }
  }
  public bool IsReusable
  {
    get
    {
      return false;
    }
  }
}