I am tryingt o create a pop up window for my TOS, Bad thing is I cannot edit the <header>..</header> section because it is on a 3rd party cart site. I have looked and all I can find is how to create one using javascript. Basically when someone clicks on the TOS link I want it to pop-up a window in the center of the screen where they can scroll the test, then click X to close it.

Any pointers on where I can find how to do that? Like I said, everything I have found is using JS to make it work.