diff --git a/js/cast.js b/js/cast.js
index 733b6fd..a065013 100644
--- a/js/cast.js
+++ b/js/cast.js
@@ -1,111 +1,100 @@
 /*global chrome*/
 /*jslint browser: true */
-var launchBtn, disabledBtn, stopBtn;
-var session;
-
-function receiverListener(e) {
+var castModule = (function () {
     'use strict';
-    return (e === chrome.cast.ReceiverAvailability.AVAILABLE);
-}
+    var launchBtn, disabledBtn, stopBtn, session;
 
-function onMediaDiscovered() {
-    'use strict';
-    if (launchBtn) {
-        stopBtn.classList.remove('cast_hidden');
-        launchBtn.classList.add('cast_hidden');
+    function receiverListener(e) {
+        return (e === chrome.cast.ReceiverAvailability.AVAILABLE);
     }
-}
 
-function onStopCast() {
-    'use strict';
-    stopBtn.classList.add('cast_hidden');
-    launchBtn.classList.remove('cast_hidden');
-}
-
-function updateListener() {
-    'use strict';
-    if (session.status !== chrome.cast.SessionStatus.CONNECTED) {
-        onStopCast();
+    function onMediaDiscovered() {
+        if (launchBtn) {
+            stopBtn.classList.remove('cast_hidden');
+            launchBtn.classList.add('cast_hidden');
+        }
     }
-}
 
-function sessionListener(e) {
-    'use strict';
-    session = e;
-    session.addMediaListener(onMediaDiscovered.bind(this, 'addMediaListener'));
-    session.addUpdateListener(updateListener.bind(this));
-    if (session.media.length !== 0) {
-        onMediaDiscovered('onRequestSessionSuccess', session.media[0]);
-    }
-}
-
-function stopCast() {
-    'use strict';
-    session.stop(onStopCast);
-}
-
-function onMediaError() {
-    'use strict';
-    stopCast();
-}
-
-function onRequestSessionSuccess(e) {
-    'use strict';
-    session = e;
-    var videoLink = document.getElementById('video_link'), videoURL = videoLink.dataset.video, mediaInfo = new chrome.cast.media.MediaInfo(videoURL, 'video/' + videoLink.dataset.ext), request = new chrome.cast.media.LoadRequest(mediaInfo);
-    session.loadMedia(request, onMediaDiscovered.bind(this, 'loadMedia'), onMediaError);
-}
-
-function onLaunchError(e) {
-    'use strict';
-    throw e.description;
-}
-
-function launchCast() {
-    'use strict';
-    chrome.cast.requestSession(onRequestSessionSuccess, onLaunchError);
-}
-
-function onInitSuccess() {
-    'use strict';
-    launchBtn = document.getElementById('cast_btn_launch');
-    disabledBtn = document.getElementById('cast_disabled');
-    stopBtn = document.getElementById('cast_btn_stop');
-    if (launchBtn) {
-        disabledBtn.classList.add('cast_hidden');
+    function onStopCast() {
+        stopBtn.classList.add('cast_hidden');
         launchBtn.classList.remove('cast_hidden');
-        launchBtn.addEventListener('click', launchCast, false);
-        stopBtn.addEventListener('click', stopCast, false);
     }
-}
 
-function onError(e) {
-    'use strict';
-    throw e.code;
-}
-
-function initializeCastApi() {
-    'use strict';
-    var sessionRequest = new chrome.cast.SessionRequest(chrome.cast.media.DEFAULT_MEDIA_RECEIVER_APP_ID), apiConfig = new chrome.cast.ApiConfig(sessionRequest, sessionListener, receiverListener, chrome.cast.AutoJoinPolicy.ORIGIN_SCOPED);
-    chrome.cast.initialize(apiConfig, onInitSuccess, onError);
-}
-
-function loadCastApi(loaded, errorInfo) {
-    'use strict';
-    if (loaded) {
-        initializeCastApi();
-    } else {
-        throw errorInfo;
+    function updateListener() {
+        if (session.status !== chrome.cast.SessionStatus.CONNECTED) {
+            onStopCast();
+        }
     }
-}
 
-function initCast() {
-    'use strict';
-    var intro = document.getElementById('download_intro');
-    if (intro) {
-        intro.insertAdjacentHTML('beforeend', '<img class="cast_icon" id="cast_disabled" src="img/ic_media_route_disabled_holo_light.png" alt="" title="Google Cast is not supported on this browser." /> <img class="cast_btn cast_hidden cast_icon" id="cast_btn_launch" src="img/ic_media_route_off_holo_light.png" title="Cast to ChromeCast" alt="Google Cast™" /> <img src="img/ic_media_route_on_holo_light.png" alt="Casting to ChromeCast…" title="Stop casting" id="cast_btn_stop" class="cast_btn cast_hidden cast_icon" />');
-        window.__onGCastApiAvailable = loadCastApi;
+    function sessionListener(e) {
+        session = e;
+        session.addMediaListener(onMediaDiscovered.bind(this, 'addMediaListener'));
+        session.addUpdateListener(updateListener.bind(this));
+        if (session.media.length !== 0) {
+            onMediaDiscovered('onRequestSessionSuccess', session.media[0]);
+        }
     }
-}
 
-window.addEventListener('load', initCast, false);
+    function stopCast() {
+        session.stop(onStopCast);
+    }
+
+    function onMediaError() {
+        stopCast();
+    }
+
+    function onRequestSessionSuccess(e) {
+        session = e;
+        var videoLink = document.getElementById('video_link'), videoURL = videoLink.dataset.video, mediaInfo = new chrome.cast.media.MediaInfo(videoURL, 'video/' + videoLink.dataset.ext), request = new chrome.cast.media.LoadRequest(mediaInfo);
+        session.loadMedia(request, onMediaDiscovered.bind(this, 'loadMedia'), onMediaError);
+    }
+
+    function onLaunchError(e) {
+        throw e.description;
+    }
+
+    function launchCast() {
+        chrome.cast.requestSession(onRequestSessionSuccess, onLaunchError);
+    }
+
+    function onInitSuccess() {
+        launchBtn = document.getElementById('cast_btn_launch');
+        disabledBtn = document.getElementById('cast_disabled');
+        stopBtn = document.getElementById('cast_btn_stop');
+        if (launchBtn) {
+            disabledBtn.classList.add('cast_hidden');
+            launchBtn.classList.remove('cast_hidden');
+            launchBtn.addEventListener('click', launchCast, false);
+            stopBtn.addEventListener('click', stopCast, false);
+        }
+    }
+
+    function onError(e) {
+        throw e.code;
+    }
+
+    function initializeCastApi() {
+        var sessionRequest = new chrome.cast.SessionRequest(chrome.cast.media.DEFAULT_MEDIA_RECEIVER_APP_ID), apiConfig = new chrome.cast.ApiConfig(sessionRequest, sessionListener, receiverListener, chrome.cast.AutoJoinPolicy.ORIGIN_SCOPED);
+        chrome.cast.initialize(apiConfig, onInitSuccess, onError);
+    }
+
+    function loadCastApi(loaded, errorInfo) {
+        if (loaded) {
+            initializeCastApi();
+        } else {
+            throw errorInfo;
+        }
+    }
+
+    return {
+        init: function () {
+            var intro = document.getElementById('download_intro');
+            if (intro) {
+                intro.insertAdjacentHTML('beforeend', '<img class="cast_icon" id="cast_disabled" src="img/ic_media_route_disabled_holo_light.png" alt="" title="Google Cast is not supported on this browser." /> <img class="cast_btn cast_hidden cast_icon" id="cast_btn_launch" src="img/ic_media_route_off_holo_light.png" title="Cast to ChromeCast" alt="Google Cast™" /> <img src="img/ic_media_route_on_holo_light.png" alt="Casting to ChromeCast…" title="Stop casting" id="cast_btn_stop" class="cast_btn cast_hidden cast_icon" />');
+                window.__onGCastApiAvailable = loadCastApi;
+            }
+        }
+    };
+}());
+
+window.addEventListener('load', castModule.init, false);