diff --git a/src/messenger/webim/js/compiled/chat/collections/messages.js b/src/messenger/webim/js/compiled/chat/collections/messages.js
index c9c68b26..47f2c678 100644
--- a/src/messenger/webim/js/compiled/chat/collections/messages.js
+++ b/src/messenger/webim/js/compiled/chat/collections/messages.js
@@ -5,5 +5,6 @@
  Copyright (c) 2005-2011 Mibew Messenger Community
  License: http://mibew.org/license.php
 */
-(function(b,d,f){b.Collections.Messages=d.Collection.extend({model:b.Models.Message,initialize:function(){b.Objects.server.callFunctionsPeriodically(f.bind(this.updateMessagesFunctionBuilder,this),f.bind(this.updateMessages,this))},updateMessages:function(a){a.lastId&&b.Objects.Models.thread.set({lastId:a.lastId});for(var c=[],e=0,d=a.messages.length;e<d;e++)c.push(new b.Models.Message(a.messages[e]));0<c.length&&this.add(c)},updateMessagesFunctionBuilder:function(){var a=b.Objects.Models.thread,
-c=b.Objects.Models.user;return[{"function":"updateMessages",arguments:{"return":{messages:"messages",lastId:"lastId"},references:{},threadId:a.get("id"),token:a.get("token"),lastId:a.get("lastId"),user:!c.get("isAgent")}}]},add:function(){var a=Array.prototype.slice.apply(arguments),a=d.Collection.prototype.add.apply(this,a);this.trigger("multiple:add");return a}})})(Mibew,Backbone,_);
+(function(b,d,f){b.Collections.Messages=d.Collection.extend({model:b.Models.Message,initialize:function(){this.periodicallyCalled=[];this.periodicallyCalled.push(b.Objects.server.callFunctionsPeriodically(f.bind(this.updateMessagesFunctionBuilder,this),f.bind(this.updateMessages,this)))},finalize:function(){for(var a=0;a<this.periodicallyCalled.length;a++)b.Objects.server.stopCallFunctionsPeriodically(this.periodicallyCalled[a])},updateMessages:function(a){a.lastId&&b.Objects.Models.thread.set({lastId:a.lastId});
+for(var c=[],e=0,d=a.messages.length;e<d;e++)c.push(new b.Models.Message(a.messages[e]));0<c.length&&this.add(c)},updateMessagesFunctionBuilder:function(){var a=b.Objects.Models.thread,c=b.Objects.Models.user;return[{"function":"updateMessages",arguments:{"return":{messages:"messages",lastId:"lastId"},references:{},threadId:a.get("id"),token:a.get("token"),lastId:a.get("lastId"),user:!c.get("isAgent")}}]},add:function(){var a=Array.prototype.slice.apply(arguments),a=d.Collection.prototype.add.apply(this,
+a);this.trigger("multiple:add");return a}})})(Mibew,Backbone,_);
diff --git a/src/messenger/webim/js/compiled/chat/models/avatar.js b/src/messenger/webim/js/compiled/chat/models/avatar.js
index d11f33a0..779ba26e 100644
--- a/src/messenger/webim/js/compiled/chat/models/avatar.js
+++ b/src/messenger/webim/js/compiled/chat/models/avatar.js
@@ -5,4 +5,4 @@
  Copyright (c) 2005-2011 Mibew Messenger Community
  License: http://mibew.org/license.php
 */
-(function(a,b){a.Models.Avatar=a.Models.Base.extend({defaults:{imageLink:!1},initialize:function(){a.Objects.server.registerFunction("setupAvatar",b.bind(this.apiSetupAvatar,this))},apiSetupAvatar:function(a){a.imageLink&&this.set({imageLink:a.imageLink})}})})(Mibew,_);
+(function(b,c){b.Models.Avatar=b.Models.Base.extend({defaults:{imageLink:!1},initialize:function(){this.registeredFunctions=[];this.registeredFunctions.push(b.Objects.server.registerFunction("setupAvatar",c.bind(this.apiSetupAvatar,this)))},finalize:function(){for(var a=0;a<this.registeredFunctions.length;a++)b.Objects.server.unregisterFunction(this.registeredFunctions[a])},apiSetupAvatar:function(a){a.imageLink&&this.set({imageLink:a.imageLink})}})})(Mibew,_);
diff --git a/src/messenger/webim/js/compiled/chat/modules/chat.js b/src/messenger/webim/js/compiled/chat/modules/chat.js
index 7c97c07e..3e8318bb 100644
--- a/src/messenger/webim/js/compiled/chat/modules/chat.js
+++ b/src/messenger/webim/js/compiled/chat/modules/chat.js
@@ -5,8 +5,10 @@
  Copyright (c) 2005-2011 Mibew Messenger Community
  License: http://mibew.org/license.php
 */
-(function(a){a.Objects.Models.Controls={};a.Objects.Models.Status={};var j=a.Application;j.module("Chat",{startWithParent:!1}).addInitializer(function(d){var g=a.Objects,c=a.Objects.Models,b=a.Objects.Models.Controls,h=a.Objects.Models.Status,f=new a.Layouts.Chat({model:new Backbone.Model(d.layoutsData.chat||{})});a.Objects.chatLayout=f;j.mainRegion.show(f);c.thread=new a.Models.Thread(d.thread);c.user=new a.Models.ChatUser(d.user);c.page=new a.Models.Page(d.page);var e=new a.Collections.Controls;
-c.user.get("isAgent")||(b.userName=new a.Models.UserNameControl({weight:220}),e.add(b.userName),b.sendMail=new a.Models.SendMailControl({weight:200,link:d.links.mailLink}),e.add(b.sendMail));c.user.get("isAgent")&&(b.redirect=new a.Models.RedirectControl({weight:200,link:d.links.redirectLink}),e.add(b.redirect),b.history=new a.Models.HistoryControl({weight:180,link:d.links.historyLink}),e.add(b.history));b.sound=new a.Models.SoundControl({weight:160});e.add(b.sound);b.refresh=new a.Models.RefreshControl({weight:140});
-e.add(b.refresh);d.links.sslLink&&(b.secureMode=new a.Models.SecureModeControl({weight:120,link:d.links.sslLink}),e.add(b.secureMode));b.close=new a.Models.CloseControl({weight:100});e.add(b.close);g.Collections.controls=e;f.controlsRegion.show(new a.Views.ControlsCollection({collection:e}));h.message=new a.Models.StatusMessage({hideTimeout:5E3});h.typing=new a.Models.StatusTyping({hideTimeout:5E3});g.Collections.status=new a.Collections.Status([h.message,h.typing]);f.statusRegion.show(new a.Views.StatusCollection({collection:g.Collections.status}));
-c.user.get("isAgent")||(c.avatar=new a.Models.Avatar,f.avatarRegion.show(new a.Views.Avatar({model:c.avatar})));g.Collections.messages=new a.Collections.Messages;c.messageForm=new a.Models.MessageForm(d.messageForm);f.messageFormRegion.show(new a.Views.MessageForm({model:c.messageForm}));f.messagesRegion.show(new a.Views.MessagesCollection({collection:g.Collections.messages}));c.sound=new a.Models.Sound;f.soundRegion.show(new a.Views.Sound({model:c.sound}));g.server.callFunctionsPeriodically(function(){var b=
-a.Objects.Models.thread,c=a.Objects.Models.user;return[{"function":"update",arguments:{"return":{typing:"typing",canPost:"canPost"},references:{},threadId:b.get("id"),token:b.get("token"),lastId:b.get("lastId"),typed:c.get("typing"),user:!c.get("isAgent")}}]},function(b){b.errorCode?a.Objects.Models.Status.message.setMessage(b.errorMessage||"refresh failed"):(b.typing&&a.Objects.Models.Status.typing.show(),a.Objects.Models.user.set({canPost:b.canPost||!1}))})})})(Mibew);
+(function(a){a.Objects.Models.Controls={};a.Objects.Models.Status={};var j=[],k=a.Application,l=k.module("Chat",{startWithParent:!1});l.addInitializer(function(c){var g=a.Objects,d=a.Objects.Models,b=a.Objects.Models.Controls,h=a.Objects.Models.Status,f=new a.Layouts.Chat({model:new Backbone.Model(c.layoutsData.chat||{})});a.Objects.chatLayout=f;k.mainRegion.show(f);d.thread=new a.Models.Thread(c.thread);d.user=new a.Models.ChatUser(c.user);d.page=new a.Models.Page(c.page);var e=new a.Collections.Controls;
+d.user.get("isAgent")||(b.userName=new a.Models.UserNameControl({weight:220}),e.add(b.userName),b.sendMail=new a.Models.SendMailControl({weight:200,link:c.links.mailLink}),e.add(b.sendMail));d.user.get("isAgent")&&(b.redirect=new a.Models.RedirectControl({weight:200,link:c.links.redirectLink}),e.add(b.redirect),b.history=new a.Models.HistoryControl({weight:180,link:c.links.historyLink}),e.add(b.history));b.sound=new a.Models.SoundControl({weight:160});e.add(b.sound);b.refresh=new a.Models.RefreshControl({weight:140});
+e.add(b.refresh);c.links.sslLink&&(b.secureMode=new a.Models.SecureModeControl({weight:120,link:c.links.sslLink}),e.add(b.secureMode));b.close=new a.Models.CloseControl({weight:100});e.add(b.close);g.Collections.controls=e;f.controlsRegion.show(new a.Views.ControlsCollection({collection:e}));h.message=new a.Models.StatusMessage({hideTimeout:5E3});h.typing=new a.Models.StatusTyping({hideTimeout:5E3});g.Collections.status=new a.Collections.Status([h.message,h.typing]);f.statusRegion.show(new a.Views.StatusCollection({collection:g.Collections.status}));
+d.user.get("isAgent")||(d.avatar=new a.Models.Avatar,f.avatarRegion.show(new a.Views.Avatar({model:d.avatar})));g.Collections.messages=new a.Collections.Messages;d.messageForm=new a.Models.MessageForm(c.messageForm);f.messageFormRegion.show(new a.Views.MessageForm({model:d.messageForm}));f.messagesRegion.show(new a.Views.MessagesCollection({collection:g.Collections.messages}));d.sound=new a.Models.Sound;f.soundRegion.show(new a.Views.Sound({model:d.sound}));j.push(g.server.callFunctionsPeriodically(function(){var b=
+a.Objects.Models.thread,c=a.Objects.Models.user;return[{"function":"update",arguments:{"return":{typing:"typing",canPost:"canPost"},references:{},threadId:b.get("id"),token:b.get("token"),lastId:b.get("lastId"),typed:c.get("typing"),user:!c.get("isAgent")}}]},function(b){b.errorCode?a.Objects.Models.Status.message.setMessage(b.errorMessage||"refresh failed"):(b.typing&&a.Objects.Models.Status.typing.show(),a.Objects.Models.user.set({canPost:b.canPost||!1}))}))});l.addFinalizer(function(){a.Objects.chatLayout.close();
+for(var c=0;c<j.length;c++)a.Objects.server.stopCallFunctionsPeriodically(j[c]);"undefined"!=typeof a.Objects.Models.avatar&&a.Objects.Models.avatar.finalize();a.Objects.Collections.messages.finalize();delete a.Objects.chatLayout;delete a.Objects.Models.thread;delete a.Objects.Models.user;delete a.Objects.Models.page;delete a.Objects.Models.avatar;delete a.Objects.Models.messageForm;delete a.Objects.Models.sound;delete a.Objects.Models.Controls;delete a.Objects.Models.Status;delete a.Objects.Collections.messages;
+delete a.Objects.Collections.controls;delete a.Objects.Collections.status})})(Mibew);
diff --git a/src/messenger/webim/js/compiled/chat_app.js b/src/messenger/webim/js/compiled/chat_app.js
index 5ecdf644..cee5ba5e 100644
--- a/src/messenger/webim/js/compiled/chat_app.js
+++ b/src/messenger/webim/js/compiled/chat_app.js
@@ -25,7 +25,7 @@ MibewAPIChatInteraction=function(){this.obligatoryArguments={"*":{threadId:null,
  Copyright (c) 2005-2011 Mibew Messenger Community
  License: http://mibew.org/license.php
 */
-(function(a,b){a.Models.Avatar=a.Models.Base.extend({defaults:{imageLink:!1},initialize:function(){a.Objects.server.registerFunction("setupAvatar",b.bind(this.apiSetupAvatar,this))},apiSetupAvatar:function(a){a.imageLink&&this.set({imageLink:a.imageLink})}})})(Mibew,_);
+(function(b,c){b.Models.Avatar=b.Models.Base.extend({defaults:{imageLink:!1},initialize:function(){this.registeredFunctions=[];this.registeredFunctions.push(b.Objects.server.registerFunction("setupAvatar",c.bind(this.apiSetupAvatar,this)))},finalize:function(){for(var a=0;a<this.registeredFunctions.length;a++)b.Objects.server.unregisterFunction(this.registeredFunctions[a])},apiSetupAvatar:function(a){a.imageLink&&this.set({imageLink:a.imageLink})}})})(Mibew,_);
 /*
  This file is part of Mibew Messenger project.
  http://mibew.org
@@ -116,8 +116,9 @@ MibewAPIChatInteraction=function(){this.obligatoryArguments={"*":{threadId:null,
  Copyright (c) 2005-2011 Mibew Messenger Community
  License: http://mibew.org/license.php
 */
-(function(b,d,f){b.Collections.Messages=d.Collection.extend({model:b.Models.Message,initialize:function(){b.Objects.server.callFunctionsPeriodically(f.bind(this.updateMessagesFunctionBuilder,this),f.bind(this.updateMessages,this))},updateMessages:function(a){a.lastId&&b.Objects.Models.thread.set({lastId:a.lastId});for(var c=[],e=0,d=a.messages.length;e<d;e++)c.push(new b.Models.Message(a.messages[e]));0<c.length&&this.add(c)},updateMessagesFunctionBuilder:function(){var a=b.Objects.Models.thread,
-c=b.Objects.Models.user;return[{"function":"updateMessages",arguments:{"return":{messages:"messages",lastId:"lastId"},references:{},threadId:a.get("id"),token:a.get("token"),lastId:a.get("lastId"),user:!c.get("isAgent")}}]},add:function(){var a=Array.prototype.slice.apply(arguments),a=d.Collection.prototype.add.apply(this,a);this.trigger("multiple:add");return a}})})(Mibew,Backbone,_);
+(function(b,d,f){b.Collections.Messages=d.Collection.extend({model:b.Models.Message,initialize:function(){this.periodicallyCalled=[];this.periodicallyCalled.push(b.Objects.server.callFunctionsPeriodically(f.bind(this.updateMessagesFunctionBuilder,this),f.bind(this.updateMessages,this)))},finalize:function(){for(var a=0;a<this.periodicallyCalled.length;a++)b.Objects.server.stopCallFunctionsPeriodically(this.periodicallyCalled[a])},updateMessages:function(a){a.lastId&&b.Objects.Models.thread.set({lastId:a.lastId});
+for(var c=[],e=0,d=a.messages.length;e<d;e++)c.push(new b.Models.Message(a.messages[e]));0<c.length&&this.add(c)},updateMessagesFunctionBuilder:function(){var a=b.Objects.Models.thread,c=b.Objects.Models.user;return[{"function":"updateMessages",arguments:{"return":{messages:"messages",lastId:"lastId"},references:{},threadId:a.get("id"),token:a.get("token"),lastId:a.get("lastId"),user:!c.get("isAgent")}}]},add:function(){var a=Array.prototype.slice.apply(arguments),a=d.Collection.prototype.add.apply(this,
+a);this.trigger("multiple:add");return a}})})(Mibew,Backbone,_);
 /*
  This file is part of Mibew Messenger project.
  http://mibew.org
@@ -256,11 +257,13 @@ c=""!=this.ui.message.val();c!=a.get("typing")&&a.set({typing:c})},setFocus:func
  Copyright (c) 2005-2011 Mibew Messenger Community
  License: http://mibew.org/license.php
 */
-(function(a){a.Objects.Models.Controls={};a.Objects.Models.Status={};var j=a.Application;j.module("Chat",{startWithParent:!1}).addInitializer(function(d){var g=a.Objects,c=a.Objects.Models,b=a.Objects.Models.Controls,h=a.Objects.Models.Status,f=new a.Layouts.Chat({model:new Backbone.Model(d.layoutsData.chat||{})});a.Objects.chatLayout=f;j.mainRegion.show(f);c.thread=new a.Models.Thread(d.thread);c.user=new a.Models.ChatUser(d.user);c.page=new a.Models.Page(d.page);var e=new a.Collections.Controls;
-c.user.get("isAgent")||(b.userName=new a.Models.UserNameControl({weight:220}),e.add(b.userName),b.sendMail=new a.Models.SendMailControl({weight:200,link:d.links.mailLink}),e.add(b.sendMail));c.user.get("isAgent")&&(b.redirect=new a.Models.RedirectControl({weight:200,link:d.links.redirectLink}),e.add(b.redirect),b.history=new a.Models.HistoryControl({weight:180,link:d.links.historyLink}),e.add(b.history));b.sound=new a.Models.SoundControl({weight:160});e.add(b.sound);b.refresh=new a.Models.RefreshControl({weight:140});
-e.add(b.refresh);d.links.sslLink&&(b.secureMode=new a.Models.SecureModeControl({weight:120,link:d.links.sslLink}),e.add(b.secureMode));b.close=new a.Models.CloseControl({weight:100});e.add(b.close);g.Collections.controls=e;f.controlsRegion.show(new a.Views.ControlsCollection({collection:e}));h.message=new a.Models.StatusMessage({hideTimeout:5E3});h.typing=new a.Models.StatusTyping({hideTimeout:5E3});g.Collections.status=new a.Collections.Status([h.message,h.typing]);f.statusRegion.show(new a.Views.StatusCollection({collection:g.Collections.status}));
-c.user.get("isAgent")||(c.avatar=new a.Models.Avatar,f.avatarRegion.show(new a.Views.Avatar({model:c.avatar})));g.Collections.messages=new a.Collections.Messages;c.messageForm=new a.Models.MessageForm(d.messageForm);f.messageFormRegion.show(new a.Views.MessageForm({model:c.messageForm}));f.messagesRegion.show(new a.Views.MessagesCollection({collection:g.Collections.messages}));c.sound=new a.Models.Sound;f.soundRegion.show(new a.Views.Sound({model:c.sound}));g.server.callFunctionsPeriodically(function(){var b=
-a.Objects.Models.thread,c=a.Objects.Models.user;return[{"function":"update",arguments:{"return":{typing:"typing",canPost:"canPost"},references:{},threadId:b.get("id"),token:b.get("token"),lastId:b.get("lastId"),typed:c.get("typing"),user:!c.get("isAgent")}}]},function(b){b.errorCode?a.Objects.Models.Status.message.setMessage(b.errorMessage||"refresh failed"):(b.typing&&a.Objects.Models.Status.typing.show(),a.Objects.Models.user.set({canPost:b.canPost||!1}))})})})(Mibew);
+(function(a){a.Objects.Models.Controls={};a.Objects.Models.Status={};var j=[],k=a.Application,l=k.module("Chat",{startWithParent:!1});l.addInitializer(function(c){var g=a.Objects,d=a.Objects.Models,b=a.Objects.Models.Controls,h=a.Objects.Models.Status,f=new a.Layouts.Chat({model:new Backbone.Model(c.layoutsData.chat||{})});a.Objects.chatLayout=f;k.mainRegion.show(f);d.thread=new a.Models.Thread(c.thread);d.user=new a.Models.ChatUser(c.user);d.page=new a.Models.Page(c.page);var e=new a.Collections.Controls;
+d.user.get("isAgent")||(b.userName=new a.Models.UserNameControl({weight:220}),e.add(b.userName),b.sendMail=new a.Models.SendMailControl({weight:200,link:c.links.mailLink}),e.add(b.sendMail));d.user.get("isAgent")&&(b.redirect=new a.Models.RedirectControl({weight:200,link:c.links.redirectLink}),e.add(b.redirect),b.history=new a.Models.HistoryControl({weight:180,link:c.links.historyLink}),e.add(b.history));b.sound=new a.Models.SoundControl({weight:160});e.add(b.sound);b.refresh=new a.Models.RefreshControl({weight:140});
+e.add(b.refresh);c.links.sslLink&&(b.secureMode=new a.Models.SecureModeControl({weight:120,link:c.links.sslLink}),e.add(b.secureMode));b.close=new a.Models.CloseControl({weight:100});e.add(b.close);g.Collections.controls=e;f.controlsRegion.show(new a.Views.ControlsCollection({collection:e}));h.message=new a.Models.StatusMessage({hideTimeout:5E3});h.typing=new a.Models.StatusTyping({hideTimeout:5E3});g.Collections.status=new a.Collections.Status([h.message,h.typing]);f.statusRegion.show(new a.Views.StatusCollection({collection:g.Collections.status}));
+d.user.get("isAgent")||(d.avatar=new a.Models.Avatar,f.avatarRegion.show(new a.Views.Avatar({model:d.avatar})));g.Collections.messages=new a.Collections.Messages;d.messageForm=new a.Models.MessageForm(c.messageForm);f.messageFormRegion.show(new a.Views.MessageForm({model:d.messageForm}));f.messagesRegion.show(new a.Views.MessagesCollection({collection:g.Collections.messages}));d.sound=new a.Models.Sound;f.soundRegion.show(new a.Views.Sound({model:d.sound}));j.push(g.server.callFunctionsPeriodically(function(){var b=
+a.Objects.Models.thread,c=a.Objects.Models.user;return[{"function":"update",arguments:{"return":{typing:"typing",canPost:"canPost"},references:{},threadId:b.get("id"),token:b.get("token"),lastId:b.get("lastId"),typed:c.get("typing"),user:!c.get("isAgent")}}]},function(b){b.errorCode?a.Objects.Models.Status.message.setMessage(b.errorMessage||"refresh failed"):(b.typing&&a.Objects.Models.Status.typing.show(),a.Objects.Models.user.set({canPost:b.canPost||!1}))}))});l.addFinalizer(function(){a.Objects.chatLayout.close();
+for(var c=0;c<j.length;c++)a.Objects.server.stopCallFunctionsPeriodically(j[c]);"undefined"!=typeof a.Objects.Models.avatar&&a.Objects.Models.avatar.finalize();a.Objects.Collections.messages.finalize();delete a.Objects.chatLayout;delete a.Objects.Models.thread;delete a.Objects.Models.user;delete a.Objects.Models.page;delete a.Objects.Models.avatar;delete a.Objects.Models.messageForm;delete a.Objects.Models.sound;delete a.Objects.Models.Controls;delete a.Objects.Models.Status;delete a.Objects.Collections.messages;
+delete a.Objects.Collections.controls;delete a.Objects.Collections.status})})(Mibew);
 /*
  This file is part of Mibew Messenger project.
  http://mibew.org
diff --git a/src/messenger/webim/js/source/chat/collections/messages.js b/src/messenger/webim/js/source/chat/collections/messages.js
index b256e278..42e026e8 100644
--- a/src/messenger/webim/js/source/chat/collections/messages.js
+++ b/src/messenger/webim/js/source/chat/collections/messages.js
@@ -24,13 +24,34 @@
              * Collection initializer.
              */
             initialize: function() {
+
+                /**
+                 * Contains ids of periodically called functions
+                 * @type Array
+                 */
+                this.periodicallyCalled = [];
+
                 // Periodically try to get new messages
-                Mibew.Objects.server.callFunctionsPeriodically(
-                    _.bind(this.updateMessagesFunctionBuilder, this),
-                    _.bind(this.updateMessages, this)
+                this.periodicallyCalled.push(
+                    Mibew.Objects.server.callFunctionsPeriodically(
+                        _.bind(this.updateMessagesFunctionBuilder, this),
+                        _.bind(this.updateMessages, this)
+                    )
                 );
             },
 
+            /**
+             * Collection finalizer
+             */
+            finalize: function() {
+                // Stop call functions periodically
+                for (var i = 0; i < this.periodicallyCalled.length; i++) {
+                    Mibew.Objects.server.stopCallFunctionsPeriodically(
+                        this.periodicallyCalled[i]
+                    );
+                }
+            },
+
             /**
              * Update messages if they are exist.
              * @param args {Object} An object of passed arguments
diff --git a/src/messenger/webim/js/source/chat/models/avatar.js b/src/messenger/webim/js/source/chat/models/avatar.js
index cff7a0d6..14c45d49 100644
--- a/src/messenger/webim/js/source/chat/models/avatar.js
+++ b/src/messenger/webim/js/source/chat/models/avatar.js
@@ -30,13 +30,32 @@
              * Model initializer.
              */
             initialize: function() {
+
+                /**
+                 * Contain ids of registered by the model api functions
+                 * @type Array
+                 */
+                this.registeredFunctions = [];
+
                 // Register API function
-                Mibew.Objects.server.registerFunction(
-                    'setupAvatar',
-                    _.bind(this.apiSetupAvatar, this)
+                this.registeredFunctions.push(
+                    Mibew.Objects.server.registerFunction(
+                        'setupAvatar',
+                        _.bind(this.apiSetupAvatar, this)
+                    )
                 );
             },
 
+            // Model finalizer
+            finalize: function() {
+                // Unregister api functions
+                for(var i = 0; i < this.registeredFunctions.length; i++) {
+                    Mibew.Objects.server.unregisterFunction(
+                        this.registeredFunctions[i]
+                    );
+                }
+            },
+
             /**
              * Set avatar
              * This is an API function.
diff --git a/src/messenger/webim/js/source/chat/modules/chat.js b/src/messenger/webim/js/source/chat/modules/chat.js
index 3c483903..c847c3cb 100644
--- a/src/messenger/webim/js/source/chat/modules/chat.js
+++ b/src/messenger/webim/js/source/chat/modules/chat.js
@@ -18,6 +18,12 @@
      */
     Mibew.Objects.Models.Status = {};
 
+    /**
+     * Contains ids of periodically called functions
+     * @type Array
+     */
+    var periodicallyCalled = [];
+
 
     // Create shortcut for Application object
     var app = Mibew.Application;
@@ -43,6 +49,7 @@
         // Show layout at page
         app.mainRegion.show(layout);
 
+
         // Initialize Thread and User
         models.thread = new Mibew.Models.Thread(options.thread);
         models.user = new Mibew.Models.ChatUser(options.user);
@@ -177,49 +184,97 @@
 
         // TODO: May be move it somewhere else
         // Periodically call update function at the server side
-        objs.server.callFunctionsPeriodically(
-            function() {
-                // Get thread and user objects
-                var thread = Mibew.Objects.Models.thread;
-                var user = Mibew.Objects.Models.user;
+        periodicallyCalled.push(
+            objs.server.callFunctionsPeriodically(
+                function() {
+                    // Get thread and user objects
+                    var thread = Mibew.Objects.Models.thread;
+                    var user = Mibew.Objects.Models.user;
 
-                // Build functions list
-                return [
-                    {
-                        "function": "update",
-                        "arguments": {
-                            "return": {
-                                'typing': 'typing',
-                                'canPost': 'canPost'
-                            },
-                            "references": {},
-                            "threadId": thread.get('id'),
-                            "token": thread.get('token'),
-                            "lastId": thread.get('lastId'),
-                            "typed": user.get('typing'),
-                            "user": (! user.get('isAgent'))
+                    // Build functions list
+                    return [
+                        {
+                            "function": "update",
+                            "arguments": {
+                                "return": {
+                                    'typing': 'typing',
+                                    'canPost': 'canPost'
+                                },
+                                "references": {},
+                                "threadId": thread.get('id'),
+                                "token": thread.get('token'),
+                                "lastId": thread.get('lastId'),
+                                "typed": user.get('typing'),
+                                "user": (! user.get('isAgent'))
+                            }
                         }
+                    ]
+                },
+                function(args) {
+                    // Check if there was an error
+                    if (args.errorCode) {
+                        Mibew.Objects.Models.Status.message.setMessage(
+                            args.errorMessage || 'refresh failed'
+                        );
+                        return;
                     }
-                ]
-            },
-            function(args) {
-                // Check if there was an error
-                if (args.errorCode) {
-                    Mibew.Objects.Models.Status.message.setMessage(
-                        args.errorMessage || 'refresh failed'
-                    );
-                    return;
+                    // Update typing status
+                    if (args.typing) {
+                        Mibew.Objects.Models.Status.typing.show();
+                    }
+                    // Update user
+                    Mibew.Objects.Models.user.set({
+                        canPost: args.canPost || false
+                    });
                 }
-                // Update typing status
-                if (args.typing) {
-                    Mibew.Objects.Models.Status.typing.show();
-                }
-                // Update user
-                Mibew.Objects.Models.user.set({
-                    canPost: args.canPost || false
-                });
-            }
+            )
         );
+
+    });
+
+
+    // Add module finalizer
+    chat.addFinalizer(function() {
+        // Close layout
+        Mibew.Objects.chatLayout.close();
+
+
+        // Stop call functions periodically
+        for (var i = 0; i < periodicallyCalled.length; i++) {
+            Mibew.Objects.server.stopCallFunctionsPeriodically(
+                periodicallyCalled[i]
+            );
+        }
+
+        // Run models finalizers
+        // TODO: may be automate this process
+        // Finalize avatar model
+        if (typeof Mibew.Objects.Models.avatar != 'undefined') {
+            Mibew.Objects.Models.avatar.finalize();
+        }
+
+        // Run collections finalizers
+        // Finalize messages collection
+        Mibew.Objects.Collections.messages.finalize();
+
+        // Clean up memory
+        // Delete layout
+        delete Mibew.Objects.chatLayout;
+
+        // Delete models
+        delete Mibew.Objects.Models.thread;
+        delete Mibew.Objects.Models.user;
+        delete Mibew.Objects.Models.page;
+        delete Mibew.Objects.Models.avatar;
+        delete Mibew.Objects.Models.messageForm;
+        delete Mibew.Objects.Models.sound;
+        delete Mibew.Objects.Models.Controls;
+        delete Mibew.Objects.Models.Status;
+
+        // Delete collections
+        delete Mibew.Objects.Collections.messages;
+        delete Mibew.Objects.Collections.controls;
+        delete Mibew.Objects.Collections.status;
     });
 
 })(Mibew);
\ No newline at end of file