need help integrating a pop-under on my website

I have a directory running phpld 3.1.0 with the bliss template, and i can't seem to figure out where to add the pop-under code.

It states in the directions to place the code between the body tags, but the directory is php. the ad network is paypopup.com.

i am sure that this is simple, and i am just missing the point,

thanks for anyone that can help.

 

Hope this helps you:
http://www.designerwiz.com/JavaScripts/popunder_pop_window.htm

 

If it just has to be between the Body tags, you should be able to put it anywhere you would put a regular banner ad, or something similar.