Jquery实现无闪烁定时刷新的代码

/*第一次读取最新通知*/
  setTimeout(function() {
             Push();
           },
        200);
      /*30轮询读取函数*/
        setInterval(function() {

            Push();

    },
        30000);

/*请求函数的ajax*/

function Push() {
    $.ajax({
        type: "POST",
        url: "/index.php?s=Push&a=index",
        data: {
            t: 3
        },
        beforeSend: function() {},
        success: function(data) {

            var obj = eval("(" + data + ")");
            // alert(obj.sixin);
            if (obj.sixin != 0) {

                $(".tongzhi").html(obj.sixin).show();

            } else {
                $(".tongzhi").html(0).hide();
            }
        }
    });

function get_data()
{
$.ajax({
url: 'getjson.php',
success: function(data) {
$('.result').html(data);
}
});
}

setInterval("get_data()",3000);//3秒一次执行

$.ajax({
url: 'ajax/test.html',
success: function(data) {
$('.result').html(data);
}
});

http://api.jquery.com/jQuery.ajax/