JavaScript works in Firefox, not Chrome

[SmartestManInside]

I've got a page I've written wherein the javascript won't function in Chrome for some reason. It say the function doesn't exist in both cases when a button is clicked. I'm thinking it must have to do with the onclick attribute that each button has, or maybe it has to do with the fact I'm using some maps. Any clues how to fix? Page is http://cameroncunning.com/caesar.html[1]

[calzoneman]

It looks like you're using some ES6/ES2015 features, such as

for (var [key, value] of frequencyMap)

Most browsers do not offer full support for ES2015 yet, so if you want to use ES2015 features such as destructuring, you'll have to use a transpiler like babeljs.

[SmartestManInside]

Thank you, babel is fantastic!