Closing a browser window

[TobiT]

I am trying to close a browser window down while opening another window by using the Window.Close(). However, a message box come saying "The web page you are viewing is trying to close the window. Are you sure you want to close it?" I want to suppress this message box so that the user does not see this. I have read that if the window wasn't opened in code then closing it in code causes these message box to pop up in both Internet Explorer and Navigator

Can somebody tell me how I can suppress this message box.

Tobi Tikare