检测移动浏览器[重复]

有我的用户代理代码：

<?phpfunction check_user_agent ( $type = NULL ) {        $user_agent = strtolower ( $_SERVER['HTTP_USER_AGENT'] );        if ( $type == 'bot' ) {     // matches popular bots     if ( preg_match ( "/googlebot|adsbot|yahooseeker|yahoobot|msnbot|watchmouse|pingdom.com|feedfetcher-google/", $user_agent ) ) {  return true;  // watchmouse|pingdom.com are "uptime services"     }        } else if ( $type == 'browser' ) {     // matches core browser types     if ( preg_match ( "/mozilla/|opera//", $user_agent ) ) {  return true;     }        } else if ( $type == 'mobile' ) {     // matches popular mobile devices that have small screens and/or touch inputs     // mobile devices have regional trends; some of these will have varying popularity in Europe, Asia, and America     // detailed demographics are unknown, and South America, the Pacific Islands, and Africa trends might not be represented, here     if ( preg_match ( "/phone|iphone|itouch|ipod|symbian|android|htc_|htc-|palmos|blackberry|opera mini|iemobile|windows ce|nokia|fennec|hiptop|kindle|mot |mot-|webos/|samsung|sonyericsson|^sie-|nintendo/", $user_agent ) ) {  // these are the most common  return true;     } else if ( preg_match ( "/mobile|pda;|avantgo|eudoraweb|minimo|netfront|brew|teleca|lg;|lge |wap;| wap /", $user_agent ) ) {  // these are less common, and might not be worth checking  return true;     }        }        return false;}?>

如何使用：

<?php$ismobile = check_user_agent('mobile');if($ismobile) {return 'yes';} else {return 'no';}?>