Ajax

//獲取請求對象
var xmlhttp;
var xmlDom;
function makeRequest() {
if (window.XMLHttpRequest) {
xmlhttp = new XMLHttpRequest();
} else {
if (window.ActiveXObject) {
xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
}
}
//具體調用函數
function getAjaxRequest(url) {
makeRequest();
xmlhttp.open("get", url, true);
xmlhttp.onreadystatechange = callback;
xmlhttp.setRequestHeader("Content-Type", "text/html;charset=UTF-8");
xmlhttp.send(null);
}
//回調函數
function callback() {
if (xmlhttp.readyState == 4) {
if (xmlhttp.status == 200) {
xmlDom = xmlhttp.responseXML;
//請求成功後執行的JS方法
}
}
}