var getJSON = function(url) {

    return new Promise(function(resolve, reject) {

    var post = new XMLHttpRequest();

    post.open('get', url, true);

    post.responseType = 'json';

    post.onload = function() {

      var status = post.status;

      if (status == 200) {

        resolve(post.response);

      } else {

        reject(status);

      }

    };

    post.send();

  });

};

getJSON('http://ws.audioscrobbler.com/2.0/?method=user.getrecenttracks&user=hopollo&api_key=ecb2e8dafb046d7fb3cd906bd866808e&format=json').then(function(data) {

	json_obj = data;

	song_name = json_obj.recenttracks.track[0].name;

	artist_name = json_obj.recenttracks.track[0].artist['#text'];

    //alert("Lecture : " + song_name + ' - ' + artist_name); //you can comment this, i used it to debug

	//console.log(json_obj)

    //result.innerHTML(song_name + artist_name); //display the result in an HTML element

	//JSON.stringify("Lecture : " + song_name + " - " + artist_name);

	//document.getElementById("song").innerHTML = "test";

	document.body.innerHTML = song_name + " - " + artist_name;

	//document.open();
	//document.write(song_name + " - " + artist_name);
	//document.close();

	//console.log(song_name + " - " + "artist_name");
	//var str = document.getElementById("demo").innerHTML;
	//var res = str.replace("Undefined", song_name);
	//document.getElementById("demo").innerHTML = res;

}, function(status) { //error detection....

  document.body.innerHTML = "unable to retrieve song name.";

});