Automatic trial user login

I need to make the trials user connect automatically to internet , without having to press click here from page via browser

so when the user connect to the accesspoint he can find internet
and the timer begin.

a suggestion,
you can create a login page with auto submit let say in 1 second.

user will get the login page but it will auto login as trial user.
from there u can pre-configure in routerboard for the user access time (trial account).

this will more better way.