I used the following code to remove script, link tags from my string,
$contents='<script>inside tag</script>hfgkdhgjh<script>inside 2</script>';
$ss=preg_replace('#<script(.*?)>(.*?)</script>#is', '', $contents);
echo htmlspecialchars($ss);
it works fine. But can I use anything that similar to html parsing rather than preg_match for this?