diff --git a/vocoder/static/vocoder.js b/vocoder/static/vocoder.js
index 79fd00e..29bc429 100644
--- a/vocoder/static/vocoder.js
+++ b/vocoder/static/vocoder.js
@@ -7,14 +7,17 @@
 // https://developer.mozilla.org/en-US/docs/web/javascript/reference
 //
 
-var serverUrl = "http://localhost:5000"; // TODO: read from environment
 var archiveUrl = serverUrl + "/add-to-archive/";
 var microphone;
+var newSoundJustRecorded = false;
+var playButton;
+var recordButton;
 var recorder;
 var recording;
 var recordingTimeout = 30000; // 30 seconds (in milliseconds)
-var newSoundJustRecorded = false;
+var serverUrl = "http://localhost:5000"; // TODO: read from environment
 var shapes = [];
+var stopButton;
 
 function record() {
   /**