Ajax asynchronous Transmission: IBM Guide-How AJAX is transmitted

IBM has just released a guide to the way Ajax is transmitted, which talks about using three ways to XMLHTTP, script tags, and frames or iframes.
For these three modes, the author most appreciate the script tags, its loading process is this
var urlstoload = [];
function processrequests ()
{
for (Var u in urlstoload)
{
var sobj = document.createelement (' script ');
SOBJ.SRC = urlstoload[U];
Document.body.appendChild (Sobj);
}
}
function Loaddoc (URL)
{
Urlstoload.push (URL);
}
if (Window.addeventlistener)
Window.addeventlistener (' Load ', processrequests, 0);
Else
Window.attachevent (' onload ', processrequests);
var url = window.location.toString ();
url = url.replace (/\/.*?$/, "sources/jsadd.php");
Loaddoc (URL);
The article also mentions the three forms of the Ajax Transfer data text, HTML, XML, JSON
I personally think that for transmission and transmission data form all have their own advantages, only according to the project needs to choose.
For data forms, using HTML, you can take advantage of the template features of the server-side scripting language. Using XML, you can apply to places where you need standard data sharing, such as stock information or weather information. Using JSON, you can use some client controls, such as ListView that require a large amount of data binding. This article links http://www.cxybl.com/html/wyzz/JavaScript_Ajax/20120721/32057.html