php判断手机并输出手机页面

我们经常使用js跳转来判断手机设备然后进行跳转，不过跳转终究是跳转，而如果使用程序来判断设备进行输出代码，不进行URL跳转岂不是更好，以下是php判断是否为手机，如果为手机就输出指定手机页面，如果不是就输出指定pc页面

<?php
//判断是否是手机
function isMobile(){
$useragent=isset($_SERVER['HTTP_USER_AGENT']) ? $_SERVER['HTTP_USER_AGENT'] : '';
$useragent_commentsblock=preg_match('|\(.*?\)|',$useragent,$matches)>0?$matches[0]:'';
function CheckSubstrs($substrs,$text){
foreach($substrs as $substr)
if(false!==strpos($text,$substr)){
return true;
}
return false;
}
$mobile_os_list=array('Google Wireless Transcoder','Windows CE','WindowsCE','Symbian','Android','armv6l','armv5','Mobile','CentOS','mowser','AvantGo','Opera Mobi','J2ME/MIDP','Smartphone','Go.Web','Palm','iPAQ');
$mobile_token_list=array('Profile/MIDP','Configuration/CLDC-','160×160','176×220','240×240','240×320','320×240','UP.Browser',
'UP.Link','SymbianOS','PalmOS','PocketPC','SonyEricsson','Nokia','BlackBerry','Vodafone','BenQ','Novarra-Vision','Iris','NetFront','HTC_','Xda_','SAMSUNG-SGH','Wapaka','DoCoMo','iPhone','iPod');
$found_mobile=CheckSubstrs($mobile_os_list,$useragent_commentsblock) || CheckSubstrs($mobile_token_list,$useragent);
if ($found_mobile){
  return true;
  }else{
  return false;
  }
}
if (isMobile()){
include("wap.html");
exit();
}else{
include("index.html");
}
?>