JSFiddle - React, Tailwind, and code Playground

HTML

<p>Kies de frisdrank:</p>
<select id="frisdrank">
    <option value="Cola">Cola</option>
    <option value="Fanta">Fanta</option>
    <option value="spuitwater">spuitwater</option>
    <option value="chocolademelk">chocolademelk</option>
</select>
<input id="OK" type="button" value="OK" onclick="foo()">
<div id="frisdrankSelected"></div>
    <script>
        function foo() {
        var e = document.getElementById("frisdrank");
        var strUser = e.options[e.selectedIndex].value;
        document.getElementById("frisdrankSelected").innerHTML = strUser;
        }
    </script>