diff --git a/js/gamepad.js b/js/gamepad.js
index 01fbd51..5596ffd 100644
--- a/js/gamepad.js
+++ b/js/gamepad.js
@@ -1,302 +1,304 @@
-$.urlParam = function(name) {
-    var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);
-    if (results === null) {
-       return null;
-    } else {
-       return decodeURIComponent(results[1]) || 0;
-    }
-};
+(function(window, document, undefined) {
+    $.urlParam = function(name) {
+        var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);
+        if (results === null) {
+           return null;
+        } else {
+           return decodeURIComponent(results[1]) || 0;
+        }
+    };
 
-var haveEvents = 'ongamepadconnected' in window;
-var gamepads = {};
-var $gamepad = $('.gamepad');
-var $nogamepad = $('.no-gamepad');
-var $help = $('.help');
-var gamepadIdentifiers = {
-    'ds4': {
-        'id': /054c.*?05c4/,
-        'colors': ['black', 'white', 'red', 'blue']
-    },
-    'xbox-one': {
-        'id': /xinput|XInput/,
-        'colors': ['black', 'white']
-    }
-};
-var gamepadHelpTimeout = null;
-var gamepadHelpDelay = 10000;
-var activeGamepadIndex = null;
-var activeGamepadType = null;
-var activeGamepadIdentifier = null;
-var activeGamepadColorIndex = null;
-var activeGamepadColorName = null;
-var activeGamepadZoomLevel = 1;
-var mapping = {
-    buttons: [],
-    axes: []
-};
+    var haveEvents = 'ongamepadconnected' in window;
+    var gamepads = {};
+    var $gamepad = $('.gamepad');
+    var $nogamepad = $('.no-gamepad');
+    var $help = $('.help');
+    var gamepadIdentifiers = {
+        'ds4': {
+            'id': /054c.*?05c4/,
+            'colors': ['black', 'white', 'red', 'blue']
+        },
+        'xbox-one': {
+            'id': /xinput|XInput/,
+            'colors': ['black', 'white']
+        }
+    };
+    var gamepadHelpTimeout = null;
+    var gamepadHelpDelay = 10000;
+    var activeGamepadIndex = null;
+    var activeGamepadType = null;
+    var activeGamepadIdentifier = null;
+    var activeGamepadColorIndex = null;
+    var activeGamepadColorName = null;
+    var activeGamepadZoomLevel = 1;
+    var mapping = {
+        buttons: [],
+        axes: []
+    };
 
-window.addEventListener("gamepadconnected", onGamepadConnect);
-window.addEventListener("gamepaddisconnected", onGamepadDisconnect);
-window.addEventListener("keydown", onKeyDown);
-
-displayGamepadHelp();
-function displayGamepadHelp() {
-    gamepadHelpTimeout = window.setTimeout(function() {
-        $nogamepad.fadeIn();
-    }, gamepadHelpDelay);
-}
-function hideGamepadHelp() {
-    window.clearTimeout(gamepadHelpTimeout);
-    $nogamepad.hide();
-}
-
-function onGamepadConnect(e) {
-    addGamepad(e.gamepad);
-}
-
-function onGamepadDisconnect(e) {
-    removeGamepad(e.gamepad.index);
-}
-
-function onKeyDown(e) {
-    switch (e.code) {
-        case "Delete":
-        case "Escape":
-            removeGamepad(activeGamepadIndex);
-            break;
-        case "KeyC":
-            changeGamepadColor();
-            break;
-        case "KeyH":
-            toggleHelp();
-            break;
-        case "NumpadAdd":
-        case "Equal":
-            changeZoom("+");
-            break;
-        case "NumpadSubtract":
-        case "Minus":
-            changeZoom("-");
-            break;
-        case "Numpad0":
-        case "Digit0":
-            changeZoom("0");
-            break;
-    }
-}
-
-function getGamepads() {
-    return navigator.getGamepads ? navigator.getGamepads() : (navigator.webkitGetGamepads ? navigator.webkitGetGamepads() : []);
-}
-
-function addGamepad(gamepad) {
-    gamepads[gamepad.index] = gamepad;
-}
-
-function removeGamepad(gamepadIndex) {
-    if (gamepadIndex === activeGamepadIndex) {
-        activeGamepadIndex = null;
-        $gamepad.empty();
-    }
-    delete gamepads[gamepadIndex];
+    window.addEventListener("gamepadconnected", onGamepadConnect);
+    window.addEventListener("gamepaddisconnected", onGamepadDisconnect);
+    window.addEventListener("keydown", onKeyDown);
 
     displayGamepadHelp();
-}
-
-setInterval(scanGamepads, 500);
-function scanGamepads() {
-    if (null !== activeGamepadIndex) {
-        return;
+    function displayGamepadHelp() {
+        gamepadHelpTimeout = window.setTimeout(function() {
+            $nogamepad.fadeIn();
+        }, gamepadHelpDelay);
+    }
+    function hideGamepadHelp() {
+        window.clearTimeout(gamepadHelpTimeout);
+        $nogamepad.hide();
     }
 
-    gamepads = getGamepads();
-    for (var gamepadIndex = 0; gamepadIndex < gamepads.length; gamepadIndex++) {
-        var gamepad = gamepads[gamepadIndex];
-        if (gamepad) {
-            if (gamepad.index in gamepads) {
-                gamepads[gamepad.index] = gamepad;
+    function onGamepadConnect(e) {
+        addGamepad(e.gamepad);
+    }
+
+    function onGamepadDisconnect(e) {
+        removeGamepad(e.gamepad.index);
+    }
+
+    function onKeyDown(e) {
+        switch (e.code) {
+            case "Delete":
+            case "Escape":
+                removeGamepad(activeGamepadIndex);
+                break;
+            case "KeyC":
+                changeGamepadColor();
+                break;
+            case "KeyH":
+                toggleHelp();
+                break;
+            case "NumpadAdd":
+            case "Equal":
+                changeZoom("+");
+                break;
+            case "NumpadSubtract":
+            case "Minus":
+                changeZoom("-");
+                break;
+            case "Numpad0":
+            case "Digit0":
+                changeZoom("0");
+                break;
+        }
+    }
+
+    function getGamepads() {
+        return navigator.getGamepads ? navigator.getGamepads() : (navigator.webkitGetGamepads ? navigator.webkitGetGamepads() : []);
+    }
+
+    function addGamepad(gamepad) {
+        gamepads[gamepad.index] = gamepad;
+    }
+
+    function removeGamepad(gamepadIndex) {
+        if (gamepadIndex === activeGamepadIndex) {
+            activeGamepadIndex = null;
+            $gamepad.empty();
+        }
+        delete gamepads[gamepadIndex];
+
+        displayGamepadHelp();
+    }
+
+    setInterval(scanGamepads, 500);
+    function scanGamepads() {
+        if (null !== activeGamepadIndex) {
+            return;
+        }
+
+        gamepads = getGamepads();
+        for (var gamepadIndex = 0; gamepadIndex < gamepads.length; gamepadIndex++) {
+            var gamepad = gamepads[gamepadIndex];
+            if (gamepad) {
+                if (gamepad.index in gamepads) {
+                    gamepads[gamepad.index] = gamepad;
+                }
+
+                for (var buttonIndex = 0; buttonIndex < gamepad.buttons.length; buttonIndex++) {
+                    button = gamepad.buttons[buttonIndex];
+                    if (null === activeGamepadIndex && button.pressed) {
+                        mapGamepad(gamepad);
+                    }
+                }
+            }
+        }
+    }
+
+    function mapGamepad(gamepad) {
+        var button;
+        var axis;
+
+        activeGamepadIndex = gamepad.index;
+
+        hideGamepadHelp();
+
+        for (var gamepadType in gamepadIdentifiers) {
+            if (gamepadIdentifiers[gamepadType].id.test(gamepad.id)) {
+                activeGamepadType = gamepadType;
+                activeGamepadIdentifier = gamepadIdentifiers[gamepadType];
+                activeGamepadColorIndex = 0;
+            }
+        }
+
+        $.ajax(
+            'templates/' + activeGamepadType + '/template.html', {
+                async: true
+            }
+        ).done(function(template) {
+            $gamepad.html(template);
+
+            if ($.urlParam('color')) {
+                changeGamepadColor($.urlParam('color'));
+            }
+            if ($.urlParam('c')) {
+                changeGamepadColor($.urlParam('c'));
             }
 
+            if ($.urlParam('zoom')) {
+                changeZoom($.urlParam('zoom'));
+            }
+            if ($.urlParam('z')) {
+                changeZoom($.urlParam('z'));
+            }
+
+            mapping.buttons = [];
             for (var buttonIndex = 0; buttonIndex < gamepad.buttons.length; buttonIndex++) {
                 button = gamepad.buttons[buttonIndex];
-                if (null === activeGamepadIndex && button.pressed) {
-                    mapGamepad(gamepad);
-                }
+                mapping.buttons[buttonIndex] = $('[data-button=' + buttonIndex + ']');
+            }
+
+            mapping.axes = [];
+            for (var axisIndex = 0; axisIndex < gamepad.axes.length; axisIndex++) {
+                axis = gamepad.axes[axisIndex];
+                mapping.axes[axisIndex] = $('[data-axis-x=' + axisIndex + '], [data-axis-y=' + axisIndex + '], [data-axis-z=' + axisIndex + ']');
+            }
+
+            updateVisualStatus();
+        });
+    }
+
+    function updateVisualStatus() {
+        if (null === activeGamepadIndex) {
+            return;
+        }
+
+        gamepads = getGamepads();
+        var activeGamepad = gamepads[activeGamepadIndex];
+
+        if (!activeGamepad) {
+            return;
+        }
+
+        requestAnimationFrame(updateVisualStatus);
+
+        var button;
+        var $button;
+        for (var buttonIndex = 0; buttonIndex < activeGamepad.buttons.length; buttonIndex++) {
+            $button = mapping.buttons[buttonIndex];
+            if (!$button) {
+                break;
+            }
+
+            button = activeGamepad.buttons[buttonIndex];
+
+            $button.attr('data-pressed', button.pressed);
+            $button.attr('data-value', button.value);
+
+            if ("function" === typeof updateButton) {
+                updateButton($button);
+            }
+        }
+
+        var axis;
+        var $axis;
+        for (var axisIndex = 0; axisIndex < activeGamepad.axes.length; axisIndex++) {
+            $axis = mapping.axes[axisIndex];
+            if (!$axis) {
+                break;
+            }
+
+            axis = activeGamepad.axes[axisIndex];
+
+            if ($axis.is('[data-axis-x=' + axisIndex + ']')) {
+                $axis.attr('data-value-x', axis);
+            }
+            if ($axis.is('[data-axis-y=' + axisIndex + ']')) {
+                $axis.attr('data-value-y', axis);
+            }
+            if ($axis.is('[data-axis-z=' + axisIndex + ']')) {
+                $axis.attr('data-value-z', axis);
+            }
+
+            if ("function" === typeof updateAxis) {
+                updateAxis($axis);
             }
         }
     }
-}
 
-function mapGamepad(gamepad) {
-    var button;
-    var axis;
-
-    activeGamepadIndex = gamepad.index;
-
-    hideGamepadHelp();
-
-    for (var gamepadType in gamepadIdentifiers) {
-        if (gamepadIdentifiers[gamepadType].id.test(gamepad.id)) {
-            activeGamepadType = gamepadType;
-            activeGamepadIdentifier = gamepadIdentifiers[gamepadType];
-            activeGamepadColorIndex = 0;
-        }
-    }
-
-    $.ajax(
-        'templates/' + activeGamepadType + '/template.html', {
-            async: true
-        }
-    ).done(function(template) {
-        $gamepad.html(template);
-
-        if ($.urlParam('color')) {
-            changeGamepadColor($.urlParam('color'));
-        }
-        if ($.urlParam('c')) {
-            changeGamepadColor($.urlParam('c'));
+    function changeGamepadColor(gamepadColor) {
+        if (! activeGamepadIdentifier) {
+            return;
         }
 
-        if ($.urlParam('zoom')) {
-            changeZoom($.urlParam('zoom'));
-        }
-        if ($.urlParam('z')) {
-            changeZoom($.urlParam('z'));
-        }
-
-        mapping.buttons = [];
-        for (var buttonIndex = 0; buttonIndex < gamepad.buttons.length; buttonIndex++) {
-            button = gamepad.buttons[buttonIndex];
-            mapping.buttons[buttonIndex] = $('[data-button=' + buttonIndex + ']');
-        }
-
-        mapping.axes = [];
-        for (var axisIndex = 0; axisIndex < gamepad.axes.length; axisIndex++) {
-            axis = gamepad.axes[axisIndex];
-            mapping.axes[axisIndex] = $('[data-axis-x=' + axisIndex + '], [data-axis-y=' + axisIndex + '], [data-axis-z=' + axisIndex + ']');
-        }
-
-        updateVisualStatus();
-    });
-}
-
-function updateVisualStatus() {
-    if (null === activeGamepadIndex) {
-        return;
-    }
-
-    gamepads = getGamepads();
-    var activeGamepad = gamepads[activeGamepadIndex];
-
-    if (!activeGamepad) {
-        return;
-    }
-
-    requestAnimationFrame(updateVisualStatus);
-
-    var button;
-    var $button;
-    for (var buttonIndex = 0; buttonIndex < activeGamepad.buttons.length; buttonIndex++) {
-        $button = mapping.buttons[buttonIndex];
-        if (!$button) {
-            break;
-        }
-
-        button = activeGamepad.buttons[buttonIndex];
-
-        $button.attr('data-pressed', button.pressed);
-        $button.attr('data-value', button.value);
-
-        if ("function" === typeof updateButton) {
-            updateButton($button);
-        }
-    }
-
-    var axis;
-    var $axis;
-    for (var axisIndex = 0; axisIndex < activeGamepad.axes.length; axisIndex++) {
-        $axis = mapping.axes[axisIndex];
-        if (!$axis) {
-            break;
-        }
-
-        axis = activeGamepad.axes[axisIndex];
-
-        if ($axis.is('[data-axis-x=' + axisIndex + ']')) {
-            $axis.attr('data-value-x', axis);
-        }
-        if ($axis.is('[data-axis-y=' + axisIndex + ']')) {
-            $axis.attr('data-value-y', axis);
-        }
-        if ($axis.is('[data-axis-z=' + axisIndex + ']')) {
-            $axis.attr('data-value-z', axis);
-        }
-
-        if ("function" === typeof updateAxis) {
-            updateAxis($axis);
-        }
-    }
-}
-
-function changeGamepadColor(gamepadColor) {
-    if (! activeGamepadIdentifier) {
-        return;
-    }
-
-    if (!! gamepadColor) {
-        if (! isNaN(parseInt(gamepadColor))) {
-            activeGamepadColorIndex = gamepadColor;
-            activeGamepadColorName = activeGamepadIdentifier.colors[activeGamepadColorIndex];
+        if (!! gamepadColor) {
+            if (! isNaN(parseInt(gamepadColor))) {
+                activeGamepadColorIndex = gamepadColor;
+                activeGamepadColorName = activeGamepadIdentifier.colors[activeGamepadColorIndex];
+            } else {
+                activeGamepadColorName = gamepadColor;
+                activeGamepadColorIndex = 0;
+                for (var gamepadColorName in activeGamepadIdentifier.colors) {
+                    if (activeGamepadColorName === gamepadColorName) {
+                        break;
+                    }
+                    activeGamepadColorIndex++;
+                }
+            }
         } else {
-            activeGamepadColorName = gamepadColor;
-            activeGamepadColorIndex = 0;
-            for (var gamepadColorName in activeGamepadIdentifier.colors) {
-                if (activeGamepadColorName === gamepadColorName) {
-                    break;
-                }
-                activeGamepadColorIndex++;
+            activeGamepadColorIndex++;
+            if (activeGamepadColorIndex > activeGamepadIdentifier.colors.length - 1) {
+                activeGamepadColorIndex = 0;
             }
-        }
-    } else {
-        activeGamepadColorIndex++;
-        if (activeGamepadColorIndex > activeGamepadIdentifier.colors.length - 1) {
-            activeGamepadColorIndex = 0;
+
+            activeGamepadColorName = activeGamepadIdentifier.colors[activeGamepadColorIndex];
         }
 
-        activeGamepadColorName = activeGamepadIdentifier.colors[activeGamepadColorIndex];
+        $gamepad.attr('data-color', activeGamepadColorName);
     }
 
-    $gamepad.attr('data-color', activeGamepadColorName);
-}
+    function changeZoom(zoomLevel) {
+        if (! activeGamepadIdentifier) {
+            return;
+        }
 
-function changeZoom(zoomLevel) {
-    if (! activeGamepadIdentifier) {
-        return;
+        if (! zoomLevel) {
+            return;
+        }
+
+        if ('0' === zoomLevel) {
+            activeGamepadZoomLevel = 1;
+        }
+        else if ('+' === zoomLevel && activeGamepadZoomLevel < 2) {
+            activeGamepadZoomLevel += 0.1;
+        }
+        else if ('-' === zoomLevel && activeGamepadZoomLevel > 0.2) {
+            activeGamepadZoomLevel -= 0.1;
+        }
+        else if (! isNaN(zoomLevel = parseFloat(zoomLevel))) {
+            activeGamepadZoomLevel = zoomLevel;
+        }
+
+        // hack: fix js float issues
+        activeGamepadZoomLevel = +activeGamepadZoomLevel.toFixed(1);
+
+        $gamepad.css('transform', 'translate(-50%, -50%) scale(' + activeGamepadZoomLevel + ', ' + activeGamepadZoomLevel + ')');
     }
 
-    if (! zoomLevel) {
-        return;
+    function toggleHelp(zoomLevel) {
+        $help.toggleClass('active');
     }
-
-    if ('0' === zoomLevel) {
-        activeGamepadZoomLevel = 1;
-    }
-    else if ('+' === zoomLevel && activeGamepadZoomLevel < 2) {
-        activeGamepadZoomLevel += 0.1;
-    }
-    else if ('-' === zoomLevel && activeGamepadZoomLevel > 0.2) {
-        activeGamepadZoomLevel -= 0.1;
-    }
-    else if (! isNaN(zoomLevel = parseFloat(zoomLevel))) {
-        activeGamepadZoomLevel = zoomLevel;
-    }
-
-    // hack: fix js float issues
-    activeGamepadZoomLevel = +activeGamepadZoomLevel.toFixed(1);
-
-    $gamepad.css('transform', 'translate(-50%, -50%) scale(' + activeGamepadZoomLevel + ', ' + activeGamepadZoomLevel + ')');
-}
-
-function toggleHelp(zoomLevel) {
-    $help.toggleClass('active');
-}
+})(window, document);