Block content with popup
I have a little hard problem since 2 days,
First of all I have a WordPress site with privet content,
I made a privet page with a PDF visible only for subscribers, I made the subscribe with no password and if an user is already subscribed he can only fill a form with his email and he can visit the page,
I need to make a popup appears when a visitor click the bouton of visiting that pdf with login if he is a subscriber and inscription if he is new.
Any Ideas for that please ?