Edit in JSFiddle

var socket = new FIMKSocket("wss://cloud.mofowallet.org:7986/ws/");
socket.ready(function () {
  var topic = "blockPushed";
  write("Registering the 'blockPushed' listener");
  socket.subscribe(topic, function (block) {
    write("Bingo. There is block "+block.height);
  });
  write("Listener registered, now lets wait (blocks appear on average every 30 seconds) ..");
});

<script type="text/javascript">
function write (text) {
    var p = document.createElement('pre');
    p.textContent = text;
    document.getElementById("output").appendChild(p);
}
</script>
<div id="output"></div>