--- a/index.html	Tue Oct 11 13:25:11 2016 +0800
+++ b/index.html	Tue Oct 11 13:25:44 2016 +0800
@@ -133,6 +133,7 @@
           },
 
           load: function(url) {
+            if (!url) { return; }
             loadArrayBuffer(url, function(xhr) {
               player.load(xhr.response);
               front.$el.removeClass('uk-hidden');