js纯ajax

var XMLHttpReq;

function createXMLHttpRequest() {

try {

XMLHttpReq = new ActiveXObject("Msxml2.XMLHTTP");//IE高版本创建XMLHTTP

}

catch(E) {

try {

XMLHttpReq = new ActiveXObject("Microsoft.XMLHTTP");//IE低版本创建XMLHTTP

}

catch(E) {

XMLHttpReq = new XMLHttpRequest();//兼容非IE浏览器，直接创建XMLHTTP对象

}

}

}

function sendAjaxRequest(url) {

createXMLHttpRequest(); //创建XMLHttpRequest对象

XMLHttpReq.open("post", url, true);

XMLHttpReq.onreadystatechange = processResponse; //指定响应函数

XMLHttpReq.send(null);

}

//回调函数

function processResponse() {

if (XMLHttpReq.readyState == 4) {

if (XMLHttpReq.status == 200) {

var text = XMLHttpReq.responseText;

/**

*实现回调

*/

text = window.decodeURI(text);

var cp = document.getElementById("cp");

cp.innerHTML = "";

var values = text.split("|");

for (var i = 0; i < values.length; i++) {

var temp = document.createElement("option");

temp.text = values[i];

temp.value = values[i];

cp.options.add(temp);

}

}

}

}