var w = window.innerWidth||document.documentElement.clientWidth||document.body.clientWidth;
var h = window.innerHeight||document.documentElement.clientHeight||document.body.clientHeight;
【1】contentType默认为application/x-www-form-urlencoded的情况
var url = "person.action";
var jsonStr = {"name":"ji","age":20};//object类型
var jsonArrayFinal = JSON.stringify(jsonStr);//string类
