Disabling a JS for FireFox web browser

So I am using a Parallax java script which just screws everything up for FireFox and so I just want to disable it for that browser specifically. I imagine it actually goes in the parallax.js document as there are lines of code disabling the script for mobile devices....

var android = navigator.platform.match(/Android/i);

as an example. What do I add to disable the feature for FireFox? Im no javascript coder haha.

Thanks in advance. Matt

Can we take a look at the code/implementation?

this is way too little information and depending on the User Agent to determine which browser is being used is damn stupid and you should never ever do so.