C#: How to access webBrowser child window

Hi,

I need C# experts help:
I'm building a Window's Form which use webBrowser inside.
My application investigate the document populated by the webBroser.
...
this.webBrowser1.Document.GetElementById("Id1");
...
- So fare so Good.

Now:

The Problem starts when a I click on a link which open a popup window.

How can I access the webBrowser child window document???

Please Help !!!
Many thanks,

Please have a look at this webpage:
http://www.codeproject.com/KB/script...ldorpopup.aspx
I think here you will get the solution.