jquery ajax官方文档： http://api.jquery.com/jquery.ajax/

常用的ajax形式：

$.ajax({
    url: "http://192.168.2.46:8000/account/getjson/",type: "post",dataType: "json",// 跨域使用jsonp
    contentType: "application/x-www-form-urlencoded; charset=UTF-8"
    data: {
        "user": "admin","password": "123456"
    },beforeSend: function(XMLHttpRequest) {
        // do something...
        return true;
    },success: function(data) {
        // alert(JSON.stringify(data));
        // do something...
    },complete: function(XMLHttpRequest,textStatus) {
        // textStatus的值：success,notmodified,nocontent,error,timeout,abort,parsererror 
    },error: function(XMLHttpRequest,textStatus,errorThrown) {
        // textStatus的值：null,parsererror
        // errorThrown的值：收到http出错文本，如 Not Found 或 Internal Server Error
    }
});