<!doctype html>
<title>The hidden attribute</title>
<link rel=author title=Ms2ger href=mailto:Ms2ger@gmail.com>
<link rel=help href=https://html.spec.whatwg.org/multipage/#the-hidden-attribute>
<link rel=help href=https://html.spec.whatwg.org/multipage/#hidden-elements>
<p hidden>This line should be visible.
<p>This line should not be visible.
<script>
document.getElementsByTagName("p")[0].hidden = false;
document.getElementsByTagName("p")[1].hidden = true;
</script>