PHP判断电脑还是手机访问

<?php
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())
echo '手机登录';
else
echo '电脑登录';
?>