Javascript in posts

I’ve searched through the forums and haven’t found a good answer to my problem.

I have some horizontal webcomics that are about 850X300px, and they won’t fit into my current blog theme (760px canvas, with about 500 body and 180 sidebar, with spacers). My two options are to cut up the comics and post them in a more vertical manner, or simply use a javascript pop-up with a custom window size to display each one as the user clicks on the appropriate link.

This javascript works inside an html page, but not inside a post. What do I need to do?

Of course, if anyone has other suggestions as to how to display each comic within the canvas, please let me know.