Internet Exploer Tracking

Hi,
I have a written a program to track IE window. I have opened five IE windows and all the windows are tracked (using SHDocVw.InternetExplorer browser; SHDocVw.ShellWindows shellWindows) and updated in my database.
Now I clicked on the third IE window in the series and I need to navigate to new URL... I given the URL(for eg. previously it was yahoo.com and now entered hotmail.com) .. The navigation event fired in my program and ... and now i need to identify which window has active ... how i will get the current window object ... ?
Please reply ...

Regards
Suresh