hey, no need to break a sweat over it :-) just use google :-)
<form method="get" action="http://www.google.com/search">
<input type="text" name="q" size="31"
maxlength="255" value="" />
<input type="submit" value="Google Search" />
<input type="radio" name="sitesearch" value="" />
The Web
<input type="radio" name="sitesearch"
value="yoursite.com" checked />Search This Site
</form>
And ther you have it, the power of google to search your site.