JSFiddle - React, Tailwind, and code Playground

by Daedalus

HTML

<form method="POST">
<select id="sel">
<option selected>one</option>
<option>two</option>
</select>
<input type="text" id="inpt" name="one" />
<button type="submit">
Submit
</button>
</form>

JavaScript

document.addEventListener('DOMContentLoaded', function () {
	let sel = document.getElementById('sel');
	sel.addEventListener('change', function () {
  	document.getElementById('inpt').name = sel.value
  });
});