Second Text Link Popup Throws Error

I’ve set up 3 text links on the following page:

http://www.agileaquarist.com/diy/diy-python-water-change-tool/

On initial page load, the first link shows the popup fine, until you mouse over a second link. At this point the page throws an “Uncaught TypeError: undefined is not a function” in the console and no popup is loaded. This error then continues to fire everytime you mouseover one of the links.

https://ww.wp.xz.cn/plugins/easyazon/