PHP防止JS注入正则

$a ="/<script[^>]*?>.*?</script>/si";
$keyword = preg_replace($a,' ',$_POST['searchword']);

<?php
$title="<style>ssss{'float:right'}</style>";
$title = strip_tags($title);
if(preg_match('/<style>(.*)</style>|<script>(.*)</script>|<img src=(.*)>/',$title,$info)){
$title=$info['1'];
}else{
$title = $title;
}
echo $title;