{source}
<!-- You can place html anywhere within the source tags -->

<iframe width="420" height="315" src="https://www.youtube.com/embed/oixAhq_muJ8" frameborder="0" allowfullscreen></iframe>
<script language="javascript" type="text/javascript">
// You can place JavaScript like this

</script>
<?php
// You can place PHP like this

?>
{/source}