Mobile detection php

<?php
if(! empty($_SERVER['HTTP_USER_AGENT'])){
    $useragent = $_SERVER['HTTP_USER_AGENT'];
    if( preg_match('@(iPad|iPod|iPhone|Android|BlackBerry|SymbianOS|SCH-M\d+|Opera Mini|Windows CE|Nokia|SonyEricsson|webOS|PalmOS)@', $useragent) ){
        header('Location: ./mobile/');
    }
}
?>