login pop_up

Is it possible, to place a direct link from an external page, to a login pop-up of G3?
all my albums are privates, and the users have their own home galerys chroot

I tried link to: /Gallery3/index.php/login/

but Gallery response:

>>>>>error: Sorry! don´t find
>>>>>Hey wait, you're not signed in yet!
>>>>>Maybe the page exists, but is only visible to authorized users. Please sign in to find out.

thanks very very much