Dynamic 404! SetSearch snippet (URL Rewrite compatible)

<?php
/* SetSaerch snippet.
 * Usage: simply place this code in a snippet and use it on the 404 page:
 * [!SetSaerch!]
 * [!AjaxSearch? &AS_showForm=`0` &ajaxSearch=`0`!]
 * NOTE: An AjaxSearch call NEEDS to be included after this call for this to have any effect.
 */

if (!empty($_GET['q']) && empty($_GET['AS_search'])){
	//Strip slashes and dashes to spaces and do an URL decode to clean up the query.
    $cleanQuery = strtr(urldecode($_GET['q']),"/-","  ");

	//Remove any words consisting of only 1 or 2 letters  due to AjaxSearch's limit
	$cleanQuery = preg_replace('/\b\w{1,2}\b/','',$cleanQuery);

	//Find position of last . (in case of multiple .'s)
    $dotPos = strrpos($ssStrQuery,".");  

	//If there is a . involved (so a possible extentsion)
    if ($dotPos !== false){
    	//Remove everything after (and including) the last .
        $cleanQuery = substr($cleanQuery,0,$dotPos);
    }

	//Set the POST value that AjasSearch uses.
    $_POST['search'] = $cleanQuery;
}
//Return empty handed (post contains search value)
return null;
?>

[!SetSearch!]
[!AjaxSearch? &AS_showForm=`0` &ajaxSearch=`0`!]