JSFiddle - React, Tailwind, and code Playground

by MrLister

HTML

<form action="#" method="post">
    <select id="category" onchange="document.forms[0].submit()">
        <option value="">(choose category)</option>
        <option value="one">one</option>
        <option value="two">two</option>
        <option value="three">three</option>
        <option value="four">four</option>
    </select>
    <br/>
    <select id="subcategory">
        <option value="">(choose subcategory)</option>
        <option value="">Sorry, no choices yet</option>
    </select>
</form>

JavaScript

document.getElementById('category').focus();