Search Bar in Static HTML Widget

[Several Zombies]

I'm trying to set a search bar up in the CMS using the static HTML widget, but no matter what I try, I get an error saying the security token is invalid or missing.

My code is as follows;

<div style="white-space:nowrap">
<form action="search.php?search_type=1#ads=24" method="post">
<input type="hidden" name="do" value="process" />
<input type="hidden" name="s" value="$session[sessionhash]" />
<input type="hidden" name="securitytoken" value="$bbuserinfo[securitytoken]" />
<input type="hidden" name="showposts" value="0" />
<input type="hidden" name="quicksearch" value="1" />
<input type="text" style="width:150px;" class="bginput" name="query"/>
<input style="font: bold 10px Arial" type="submit" class="button" value="Search" /></form>
<a style="text-decoration:none" href="$vboptions[bburl]/search.php" accesskey="4" rel="nofollow" id="header_search" class=""></a><!--&nbsp;-->
</div>

Any ideas?