when i click on the link to take you to the page that describes vB codes and what they do (misc.php?do=bbcode) when it loads it pops up an alert that says "Hello World"

Whats the deal with this and how do i turn it off?

its because its actually parsing the section that explains the [code] tag.

<td class="alt2">[code]<br />
<script type="text/javascript">
<!--
alert("Hello world!");
//-->
</script>
<br />
[/code]</td>