Update '12/player.js'

12/player.js

@@ -1,5 +1,5 @@
 var track = document.querySelector("track_1"), 
-	track_div = document.getElementById("track_1");
+	track_div_1 = document.getElementById("track_1");
 track_1.addEventListener('cuechange', function () {
   let cues = track_1.track_1.activeCues;  // array of current cues
   console.log("cuechange", cues, cues[0].text, cues[0].startTime, cues[0].endTime);