Show Popup on user registration page

Hello.
Thanks for the plugin. I am using buddypress with additional user fields at registration. I would like to show the terms in a pop-up window, before a new user strats to fill out the registration form. However, the pop-up window does not show up at the registration page. Any tips how to make the pop-up to show up? There is a page created for the registration page, but I assume buddypress loads its own content onto that registration page, and somehow disregards the WP Terms Popup.
Thanks,