How to make everything on a web page unclickable until something loads with Javascript

I've made my own anti-adblock program for my website with Javascript. There is a slight delay before the actual alert comes up, and during that time, users have the ability to click anything on my actual webpage.

Is there something I can add to my Javascript that makes the rest of my webpage unclickable unless no adblock is detected?

I'm aware what I can add to my CSS to make the page unclickable, but I'm not sure how I can make that only active if I detect an adblocker.