var xmlhttp;

    var doneStr = loadXMLDoc('https://www.cnblogs.com/liudongpei/p/6021170.html');

    function loadXMLDoc(url) {

        var htmldata;

        xmlhttp = null;

        if (window.XMLHttpRequest) { // code for IE7, Firefox, Opera, etc.

            xmlhttp = new XMLHttpRequest();

        } else if (window.ActiveXObject) { // code for IE6, IE5

            xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");

        }

        if (xmlhttp != null) {

            xmlhttp.onreadystatechange = function() {

                if (xmlhttp.readyState == 4) { // 4 = "loaded"

                    if (xmlhttp.status == 200) { // 200 = "OK"

                        htmldata = get_cnblogs_post_body(xmlhttp.responseText);

                    } else {

                        alert("Problem retrieving XML data:" + xmlhttp.statusText);

                    }

                }

            }

            xmlhttp.open("GET", url, false);

            xmlhttp.send(null);

        } else {

            alert("Your browser does not support XMLHTTP.");

        }

        return htmldata;

    }