diff --git a/webmusic.js b/webmusic.js
index e290c80..165dbdc 100644
--- a/webmusic.js
+++ b/webmusic.js
@@ -1,12 +1,12 @@
 'use strict';
 
-let audioPlayer  = new Audio();
-let selectedItem = 0;
-let playingItem  = 0;
-let playerState  = "idle";
-let continuous   = true;
-let repeat       = false;
-let total        = 0;
+const audioPlayer  = new Audio();
+let   selectedItem = 0;
+let   playingItem  = 0;
+let   playerState  = "idle";
+let   continuous   = true;
+let   repeat       = false;
+let   total        = 0;
 
 const handleKeyEvent = (event) => {
 	switch (event.key) {
@@ -148,7 +148,7 @@ const updateButtonState = () => {
 
 
 const playSong = (id) => {
-	let element = document.getElementById(id);
+	const element = document.getElementById(id);
 
 	if (element === null) return;
 	if (element.classList.contains('dir')) return;