纯JS脚本发送HTTP请求

var xmlHttp;
var iii = 0;
if (window.XMLHttpRequest) {
        xmlHttp = new XMLHttpRequest();
        if (xmlHttp.overrideMimeType)
            xmlHttp.overrideMimeType('text/xml');
    } else if (window.ActiveXObject) {
        try {
            xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
        } catch (e) {
            try {
                xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
            } catch (e) {
            }
        }
    }
var callback = function(e) {
        if(e.currentTarget.status == 200){ dohttp(iii)}
}
var url = ["http://*****"
            ,"http://*****"
            ,"http://*****"
            ,"http://*****"
            ,"http://*****"
            ,"http://*****"
            ,"http://*****"    
            ]
var dohttp = function(i) {
    iii = i+1;
    xmlHttp.open("GET", url[i], true);// 异步处理返回 
    xmlHttp.setRequestHeader("Authorization","bearer 0d6b6c89-3c07-4b8a-9be3-04788191e464")
    xmlHttp.onreadystatechange = callback; 
    xmlHttp.setRequestHeader("Content-Type",
            "application/x-www-form-urlencoded;");
    xmlHttp.send()
}
dohttp(0);