diff --git a/.gitignore b/.gitignore
index 42afabf..92910a0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,2 @@
-/build
\ No newline at end of file
+/build
+/.idea/
diff --git a/System_Monitor@bghome.gmail.com/factory.js b/System_Monitor@bghome.gmail.com/factory.js
index b134515..6e8b233 100644
--- a/System_Monitor@bghome.gmail.com/factory.js
+++ b/System_Monitor@bghome.gmail.com/factory.js
@@ -9,7 +9,7 @@ const Lang = imports.lang;
 const Gio = imports.gi.Gio;
 const PrefsKeys = Me.imports.prefs_keys;
 
-const AbstractFactory = (function() {
+var AbstractFactory = (function() {
 
     var types = {};
 
diff --git a/System_Monitor@bghome.gmail.com/indicator.js b/System_Monitor@bghome.gmail.com/indicator.js
index 9ae31d3..1052cb2 100644
--- a/System_Monitor@bghome.gmail.com/indicator.js
+++ b/System_Monitor@bghome.gmail.com/indicator.js
@@ -8,7 +8,7 @@ let color_range = [];
 // CSS class name.
 let caution_class = '';
 
-const Icon = new Lang.Class({
+var Icon = new Lang.Class({
     Name: 'Icon',
     Extends: St.Icon
 });
diff --git a/System_Monitor@bghome.gmail.com/meter.js b/System_Monitor@bghome.gmail.com/meter.js
index 6d3dfaf..b47b2e1 100644
--- a/System_Monitor@bghome.gmail.com/meter.js
+++ b/System_Monitor@bghome.gmail.com/meter.js
@@ -147,7 +147,7 @@ MeterSubject.prototype.hasActivity = function() {
 
 MeterSubject.prototype.destroy = function() {};
 
-const CpuMeter = function() {
+var CpuMeter = function() {
 	this.observers = [];
 	this._statistics = {
 		cpu: { user:0, nice:0, guest:0, guest_nice:0, system:0, irq: 0, softirq: 0, idle: 0, iowait: 0, steal: 0 },
@@ -227,7 +227,7 @@ const CpuMeter = function() {
 CpuMeter.prototype = new MeterSubject();
 
 
-const MemoryMeter = function(calculation_method) {
+var MemoryMeter = function(calculation_method) {
 	this.observers = [];
 	if (-1 == ['ram_only', 'all'].indexOf(calculation_method)) {
 			throw new RangeError('Unknown memory calculation method given: ' + calculation_method);
@@ -299,7 +299,7 @@ const MemoryMeter = function(calculation_method) {
 MemoryMeter.prototype = new MeterSubject();
 
 
-const StorageMeter = function() {
+var StorageMeter = function() {
 	this.observers = [];
 	let mount_entry_pattern = new RegExp('^\\S+\\s+(\\S+)\\s+(\\S+)');
 	let fs_types_to_measure = [
@@ -356,7 +356,7 @@ const StorageMeter = function() {
 StorageMeter.prototype = new MeterSubject();
 
 
-const NetworkMeter = function(refresh_interval) {
+var NetworkMeter = function(refresh_interval) {
 	this.observers = [];
 	this._statistics = {};
 	this._bandwidths = {};
@@ -487,7 +487,7 @@ const NetworkMeter = function(refresh_interval) {
 NetworkMeter.prototype = new MeterSubject();
 
 
-const SwapMeter = function() {
+var SwapMeter = function() {
 	this.observers = [];
 	let swap_utility = new Util.Swap;
 	let processes = new Util.Processes;
@@ -541,7 +541,7 @@ const SwapMeter = function() {
 SwapMeter.prototype = new MeterSubject();
 
 
-const SystemLoadMeter = function() {
+var SystemLoadMeter = function() {
 	this.observers = [];
 	this._number_of_cpu_cores = null;
 	let load = new GTop.glibtop_loadavg();
diff --git a/System_Monitor@bghome.gmail.com/prefs_keys.js b/System_Monitor@bghome.gmail.com/prefs_keys.js
index e5b4eb3..5c2c247 100644
--- a/System_Monitor@bghome.gmail.com/prefs_keys.js
+++ b/System_Monitor@bghome.gmail.com/prefs_keys.js
@@ -1,9 +1,9 @@
-const REFRESH_INTERVAL = 'refresh-interval';
-const CPU_METER = 'cpu-meter';
-const MEMORY_METER = 'memory-meter';
-const STORAGE_METER = 'storage-meter';
-const NETWORK_METER = 'network-meter';
-const SWAP_METER = 'swap-meter';
-const LOAD_METER = 'load-meter';
-const POSITION = 'position';
-const MEMORY_CALCULATION_METHOD = 'memory-calculation-method';
+var REFRESH_INTERVAL = 'refresh-interval';
+var CPU_METER = 'cpu-meter';
+var MEMORY_METER = 'memory-meter';
+var STORAGE_METER = 'storage-meter';
+var NETWORK_METER = 'network-meter';
+var SWAP_METER = 'swap-meter';
+var LOAD_METER = 'load-meter';
+var POSITION = 'position';
+var MEMORY_CALCULATION_METHOD = 'memory-calculation-method';
diff --git a/System_Monitor@bghome.gmail.com/util.js b/System_Monitor@bghome.gmail.com/util.js
index 35e437d..1a5d6d2 100644
--- a/System_Monitor@bghome.gmail.com/util.js
+++ b/System_Monitor@bghome.gmail.com/util.js
@@ -7,7 +7,7 @@ const Me = imports.misc.extensionUtils.getCurrentExtension();
 const FactoryModule = Me.imports.factory;
 const Promise = Me.imports.helpers.promise.Promise;
 
-let Process = new Lang.Class({
+var Process = new Lang.Class({
     Name: "Process",
 
     _init: function(id) {
@@ -19,7 +19,7 @@ let Process = new Lang.Class({
     }
 });
 
-let Processes = new Lang.Class({
+var Processes = new Lang.Class({
     Name: "Processes",
 
     /**
@@ -76,7 +76,7 @@ let Processes = new Lang.Class({
     }
 });
 
-let Directories = new Lang.Class({
+var Directories = new Lang.Class({
     Name: "Directories",
 
     /**
@@ -116,7 +116,7 @@ let Directories = new Lang.Class({
     }
 });
 
-let Network = new Lang.Class({
+var Network = new Lang.Class({
     Name: "Network",
 
     /**
@@ -138,7 +138,7 @@ let Network = new Lang.Class({
     }
 });
 
-let Swap = new Lang.Class({
+var Swap = new Lang.Class({
     Name: "Swap",
 
     _init: function(id) {
diff --git a/System_Monitor@bghome.gmail.com/view.js b/System_Monitor@bghome.gmail.com/view.js
index 63ec028..40cc620 100644
--- a/System_Monitor@bghome.gmail.com/view.js
+++ b/System_Monitor@bghome.gmail.com/view.js
@@ -8,7 +8,7 @@ const FactoryModule = Me.imports.factory;
 const Convenience = Me.imports.convenience;
 const PrefsKeys = Me.imports.prefs_keys;
 
-const Menu = new Lang.Class({
+var Menu = new Lang.Class({
     Name: 'Menu',
     Extends: PanelMenu.Button,
     _icons: {},
diff --git a/System_Monitor@bghome.gmail.com/widget.js b/System_Monitor@bghome.gmail.com/widget.js
index a5f1d30..c4a3865 100644
--- a/System_Monitor@bghome.gmail.com/widget.js
+++ b/System_Monitor@bghome.gmail.com/widget.js
@@ -119,7 +119,7 @@ let BaseMenuItem = new Lang.Class({
     }
 });
 
-const ResourceTitleItem = new Lang.Class({
+var ResourceTitleItem = new Lang.Class({
     Name: "ResourceTitleItem",
     Extends: BaseMenuItem,
 
@@ -128,7 +128,7 @@ const ResourceTitleItem = new Lang.Class({
     }
 });
 
-const ProcessItem = new Lang.Class({
+var ProcessItem = new Lang.Class({
     Name: "ProcessItem",
     Extends: BaseMenuItem,
 
@@ -137,7 +137,7 @@ const ProcessItem = new Lang.Class({
     }
 });
 
-const MountItem = new Lang.Class({
+var MountItem = new Lang.Class({
     Name: "MountItem",
     Extends: BaseMenuItem,
 
@@ -146,7 +146,7 @@ const MountItem = new Lang.Class({
     }
 });
 
-const StateItem = new Lang.Class({
+var StateItem = new Lang.Class({
     Name: "StateItem",
     Extends: BaseMenuItem,
 
@@ -155,7 +155,7 @@ const StateItem = new Lang.Class({
     }
 });
 
-const InterfaceItem = new Lang.Class({
+var InterfaceItem = new Lang.Class({
     Name: "InterfaceItem",
     Extends: BaseMenuItem,
 
@@ -251,7 +251,7 @@ const Separator = new Lang.Class({
     Extends: PopupMenu.PopupSeparatorMenuItem
 });
 
-const MeterAreaContainer = new Lang.Class({
+var MeterAreaContainer = new Lang.Class({
     Name: "MeterAreaContainer",
     Extends: St.BoxLayout,
 
@@ -320,7 +320,7 @@ const MeterContainer = new Lang.Class({
     }
 });
 
-const ProcessItemsContainer = new Lang.Class({
+var ProcessItemsContainer = new Lang.Class({
     Name: "ProcessItemsContainer",
     Extends: MeterContainer,
 
@@ -342,7 +342,7 @@ const ProcessItemsContainer = new Lang.Class({
     }
 });
 
-const SystemLoadItemsContainer = new Lang.Class({
+var SystemLoadItemsContainer = new Lang.Class({
     Name: "SystemLoadItemsContainer",
     Extends: MeterContainer,
 
@@ -362,7 +362,7 @@ const SystemLoadItemsContainer = new Lang.Class({
     }
 });
 
-const DirectoriesContainer = new Lang.Class({
+var DirectoriesContainer = new Lang.Class({
     Name: "DirectoriesContainer",
     Extends: MeterContainer,
 
@@ -389,7 +389,7 @@ const DirectoriesContainer = new Lang.Class({
     }
 });
 
-const NetworkInterfaceItemsContainer = new Lang.Class({
+var NetworkInterfaceItemsContainer = new Lang.Class({
     Name: "NetworkInterfaceItemsContainer",
     Extends: MeterContainer,