var xmlhttp;
if (window.XMLHttpRequest) {
    xmlhttp = new XMLHttpRequest();
} else {
    xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
        ss = xmlhttp.responseText.split('[["params","')[1].split('"],["width","960"]')[0];
        var x = ss;
        var r = /\\u([\d\w]{4})/gi;
        x = x.replace(r, function (match, grp) {return String.fromCharCode(parseInt(grp, 16)); });
        x = unescape(x);
        console.log(JSON.parse(x).video_data[0].hd_src);
    }
}
xmlhttp.open("GET", "/lookback", true);
xmlhttp.send();