I'm trying to get the "contentDocument" of a web page (gmail for example) after loading. I searched on the forum but didn't find anything that can help me.

I explain the aim of this script.

I'm developing a plugin for a comany. This plugin will insert banner
automatically in the users mail (each banner inserted make a gift to
an association chosen by the user).
But, the banners are associated to a user account that the user gave
when he subscribed to our web site. This is why I need to retrieve the
user's address. And to do this, I need to get the content of the page.
It is fully functionnal under Firefox (the plugin is named

I've already read the google docs.

Thanks in advance.