Is it possible to write unit tests for inline JavaScript? If so, how?

I have written a simple one page application which takes an input from a form, processes it in JavaScript, then outputs back to the page in HTML. However I have no idea, how to (or even if I can) write unit tests for it. It is probably simple enough not to need unit tests, but I thought it would be a good learning process.

I have kept the JavaScript inline in the HTML file, as it will be distributed manually to offline PCs, so need to keep everything to one file.