ajax的一个最简单例子
{"Money":2000.00,"Age":21} <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML> <HEAD> <TITLE> New Document </TITLE> <META NAME="Generator" CONTENT="EditPlus"> <META NAME="Author" CONTENT=""> <META NAME="Keywords" CONTENT=""> <META NAME="Description" CONTENT=""> <script type="text/javascript" src="shopajax.js"></script> </HEAD> <BODY> <div id="as"></div> 
<SCRIPT LANGUAGE="JavaScript"> 
<!-- var ajax=new xmlhttp(); debugger ajax.getopen("1.html"); 
function callpage(){ 
if(ajax.status==0){//本地为0，远程为200 var obj=eval('('+ajax.text+')'); document.getElementById("as").innerHTML="年纪："+obj.Age+"<br>薪水："+obj.Money; 
} } 
//--> </SCRIPT> </BODY> </HTML> shopajax.js：
function requestHttp(){ var request; if(window.XMLHttpRequest) { request = new XMLHttpRequest(); if(request.overrideMimeType) {request.overrideMimeType('text/xml'); } } else if(window.ActiveXObject) { var versions = ['Microsoft.XMLHTTP', 'MSXML.XMLHTTP', 'Microsoft.XMLHTTP', 'Msxml2.XMLHTTP.7.0', 'Msxml2.XMLHTTP.6.0', 'Msxml2.XMLHTTP.5.0', 'Msxml2.XMLHTTP.4.0', 'MSXML2.XMLHTTP.3.0', 'MSXML2.XMLHTTP']; for(var i=0; i<versions.length; i++) {try {request = new ActiveXObject(versions[i]);break;} catch(e) {} } } return request; } function xmlhttp(){ this.r=requestHttp(); } xmlhttp.prototype.postopen=function(url,data){ this.r.open('POST',url,false); this.r.setrequestheader("content-type","application/x-www-form-urlencoded"); this.r.onreadystatechange = ReadyStateChange(this); if(typeof(data)=='undefined') this.r.send(); else this.r.send(data); } xmlhttp.prototype.getopen=function(url){ if(window.XMLHttpRequest) {this.r.open('GET',url); this.r.onreadystatechange = ReadyStateChange(this); this.r.send(null); } else { this.r.open("GET", url, true); this.r.onreadystatechange = ReadyStateChange(this); this.r.send(); } } ReadyStateChange=function(obj){ return function(){ if(obj.r.readyState==4){ obj.status=obj.r.status; obj.text=obj.r.responseText; obj.body=obj.r.responseBody; callpage(); } } } 1.html:
