How to connect a script on Phonegap?

Question

JavaScript

The crux of the matter is this. There is an application developed by phonegap, when launched, it first opens a local index file, we check the connection to the Internet, when connected, it goes to another site.
Is it possible to add sctipt to phonegap
JS
jquery.checknet-1.6.min.js
jquery-1.9.1.min.js
css
checknet.css