detecting Ipad and Iphone browsers

<?php
$isIpad     = stripos($_SERVER['HTTP_USER_AGENT'], 'iPad') !== false ? true : false;
$redirectOnIpadTo = $modx->getOption('redirectOnIpadTo', $scriptProperties, false);
$redirectOnIpadTo = $redirectOnIpadTo == $modx->resource->get('id') ? false : $redirectOnIpadTo;

$modx->setPlaceholder('isIpad', $isIpad);

if ($isIpad == true && (int)$redirectOnIpadTo > 0) {
    $modx->sendRedirect($modx->makeUrl($redirectOnIpadTo));

}
return;

<?php
/* Snippet Title: CustomCSS  */

$output = '';
$cssBase = $modx->config['site_url'] . 'one/css/';   /* or wherever you keep your css files */

/* array of browser agent names and their respective .css filenames */

$browserArray = array(
     'iPhone' => 'mobile-screen.css',
     'SymbianOS/9.1' => 'mobile-screen.css',
     'anotherbrowser' => 'mobile-screen.css',
     'yetanother browser' => 'mobile-screen.css'
);

/* see if we recognize one */
foreach ($browserArray as $key => $value) {
    if (strpos($_SERVER['HTTP_USER_AGENT'],$key)) {
        $output .= $cssBase . $value;
        break;
    }
}

/* if we didn't find one, use the default css file */
if ($output == '') {
    $output = $cssBase . 'screen.css';
}

return $output;