сценарий в теле

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<div id="d1"></div>
<script>
document.getElementById('d1').innerHTML='<h1>Hello World!</h1>';
</script>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
</head>
<body>
<div id="d1"></div>
<script>
document.getElementById('d1').innerHTML='<h1>Hello World!</h1>';
</script>
</body>
</html>