Can't figure out javascript use

I developed this WP site six years ago and now want to modify how a page opens pop-up windows for video. But I can’t remember or figure out how I did it before. I know I used javascript to open the windows, and I can see the javascript when viewing the page source. But when I edit that page in WP, that javascript isn’t there. FYI, as a coder I’m monkey-see monkey-do.

Here’s the page. Clicking on any of the images or “play video” links pops up a new small window that contains a youtube video. How do I find and access the javascript that appears in the page source view?

http://ca-bankruptcylaw.com/bankruptcy-info/videos