Run ExtJs 4 with ExtJs 2 at the same time

Hi. How it's possible to use at the same time, on one page, both Ext2 and Ext4?

I think I can add namespace support to Ext2 libraries. But may be somebody knows more easiest way, without rewriting a whole framework?

Code:

// after loading ExtJS 2

var ext2 = {};
ext2.Ext = Ext;

// then loading ExtJS 4

We have a large and huge project on ExtJS 2. About one year ago we made a new functionality for our project on ExtJS 4. Now we have some functionality on 2 and 4 versions. They work separately but have one server side.

At that moment we want to migrate from 2 to 4 but it's impossible caues it takes too much time. So we decided to make it step by step. And integrate some functionality from ExtJS 4 to ExtJS 2. For example, calling user search window and return in callback results.

P.S. Sorry for my English.

Run ExtJs 4 with ExtJs 2 at the same time