以前大家都用
<script type="text/javascript">
<!-- // hide from really old browsers that noone uses anymore
// also hide from browsers that use the XHTML DTD
// content of your Javascript goes here
// -->
</script>
而现在提倡以下的格式，这才是更有意义的html。
<script type="text/javascript">
/* <![CDATA[ */
// content of your Javascript goes here
/* ]]> */
</script>
学习自：Javascript and XHTML