How to Insert a Couple of Lines of Code on Every Page

In version 2.x of the cart I used a live chat software that also helped me keep track of visitors on my site. I inserted a few lines of code into a certain file which was near the bottom of the page, just before the closing body tag. I can’t seem to find anywhere to do that in version 3.x. Can someone point me in the right direction?

skins/your skin/ customer/


Add an html block in Default location should also work.

Thanks guys. I found that johnbol1's suggestion works if I put {literal} tags around the code.