如何使用Javascript而不是jQuery从HTML表单数据生成JSON列表?

Sorry if questions like this get really annoying; I've tried to figure this out without bothering anyone, but I'm a beginner and I'm totally stumped. Here's what I have so far. I want to pull data from the form called "paymentform" and generate a JSON list that I can post in a REST call. My boss wants me to do this specifically with JavaScript rather than jQuery. How would I do that?Sorry if questions like this get really annoyin