How to close Rediff mail advertisement popup window

[Jack]

Hi,

I am automating Rediff mail to get experience on Selenium.

Whenever, a user login to Rediff mail by entering username, password
and clicking on 'Go' button, there comes a advertisement popup. I want
to get access to that advertisement popup and close it.
(If you do not see the popup, in Firefox, go to Tools-->Options--
>Content tab-->deselect 'Block pop-up windows')

I did try many ways, but stills no go. Please, could some one have a
look into this or atleast give an idea on how to get access to this
advertisement popup.

I am using:
Selenium RC(selenium-server-standalone-2.15.0)
Perl
Firfox v 10.0.2

Thanks
Jack