Java script problems in body

There’s a nice little bit of Java script to help protect email addresses and other contact info from being picked up by spam bots:

https://joemaller.com/js-mailer.shtml

I tried using it in a WordPress page, but a problem occurs. All the single quotes are converted to #8216 and #8217 codes instead of being left alone as plain text single quotes. The result: the Java doesn’t work.

I have scrubbed and scrubbed my code to ensure that I’m putting only absolutely pristine plain text single quotes into the Page body, and I’ve ensured that the visual editor is turned off. I’m not sure why these conversions should be taking place.

Any ideas?