This is a purify function to ensure user-inputed string is sanitized and prevent XSS kind of attacks.
function purify($input){
$result = "";
if (isset($input) && !empty($input)) {
$result = rawurldecode($input);
$result = strip_tags($result);
$result = stripcslashes($result);
$result = htmlspecialchars($result, ENT_QUOTES);
$result = iconv('utf-8','utf-8//IGNORE',$result);
}
return $result;
}