javascript output random line from input

Is there a way to chose a random line from an input or textarea with a javascript?

Currently I find a few results that seems to be working, but mostly use jquery and other additional languages. I'm looking for Javascript only. I've seen javascripts that pick a random line from a local file, I know how that works, but is there a way to do it without local file, and just from an input?

Thanks for your help!