div+ajax 实现网页框架布局

核心代码：

function fnSuccMainBody(xhr){
// main body
document.getElementById("main").innerHTML = xhr.responseText;

// sub : sub body
if(document.getElementById("submain") != null)
ShowComments();
}

function fnSuccSubMainBody(xhr){
document.getElementById("submain").innerHTML = xhr.responseText;
}

function AjaxRequest(url, data, fnSucc)
{
var xhr = window.XMLHttpRequest ? new XMLHttpRequest() : new ActiveXObject('Microsoft.XMLHTTP');

xhr.onreadystatechange = function(){
AjaxCallBack(xhr, fnSucc);
};

xhr.open("post", url, true);
xhr.setRequestHeader('Content-type', 'application/x-www-form-urlencoded;');

xhr.send(data);
}

function AjaxCallBack(xhr, fnSucc)
{
if(xhr.readyState == 4)
{
var s = xhr.status;
if(s >= 200 && s < 300)
fnSucc(xhr);
else
;
}
}

// 调用
function showMain()
{
var url = xxx;
var data = xxx;
AjaxRequest(url, data, fnSuccMainBody);
}

function showSubMain()
{
var url = xxx;
var data = xxx;
AjaxRequest(url, data, fnSuccSubMainBody);
}
参考：

div+ajax实现类似iframe功能
http://lz12366.iteye.com/blog/1137458
frameset和div常规布局的优缺点比较
http://blog.csdn.net/zhangxinrun/article/details/5677829