There are lots of ways of structuring the code, but usually by checking scrolldepth. If you want to add this to your own site, checkout jQuery ScrollDepth: htt

There are lots of ways of structuring the code, but usually by checking scrolldepth. If you want to add this to your own site, checkout jQuery ScrollDepth: https://github.com/robflaherty/jquery-scrolldepth https://github.com/robflaherty/jquery-scrolldepth