How did this guy do this?

hey i got a quick question (i already used the search button)

check this site - narutospot(dot)net

and click on any category. there will be a pop up window with a cpa offer

so basically when you click on a category you will be redirected to the real link and then a pop up will show that offers a cpa.

any of you guys know how to do this thing?

it seems so simple but i know nothing about html!

please help