choose.html

<!DOCTYPE html>
<html>
<body>

<p>
JavaScript can write directly into the HTML output stream:
</p>

<script>
document.write("<h1>This is a heading</h1>");
document.write("<p>This is a paragraph.</p>");
</script>

<p>
You can only use <strong>document.write</strong> in the HTML output.
If you use it after the document has loaded (e.g. in a function), the whole document will be overwritten.
</p>

</body>
</html>