isolated script scope

js/gamepad.js

@@ -1,3 +1,4 @@
+(function(window, document, undefined) {
     $.urlParam = function(name) {
         var results = new RegExp('[\?&]' + name + '=([^&#]*)').exec(window.location.href);
         if (results === null) {
@@ -300,3 +301,4 @@ function changeZoom(zoomLevel) {
     function toggleHelp(zoomLevel) {
         $help.toggleClass('active');
     }
+})(window, document);