PHP code to determine whether the access source is a mobile phone and automatically jump

<?php
$ua = strtolower($_SERVER['HTTP_USER_AGENT']);
$uachar = "/(nokia|sony|ericsson|mot|samsung|sgh|lg|philips|panasonic|
alcatel|lenovo|cldc|midp|mobile)/i";
if(($ua == '' || preg_match($uachar, $ua))&& !strpos(strtolower($_SERVER['REQUEST_URI']),'wap'))
{
    $Loaction = 'mobile/';
    if (!empty($Loaction))
    {
       header("Location: $Loaction\n");
        exit;
    }
}
?>

<?php
$is_wap = 0; 
if(strpos($_SERVER['HTTP_VIA'],"wap")>0){$is_wap = 1;}
  elseif(strpos(strtoupper($_SERVER['HTTP_ACCEPT']),"VND.WAP") > 0 || strpos(strtoupper($_SERVER['HTTP_ACCEPT']),"UC/") > 0){
  $is_wap = 1;}
  else { 
      $iUSER_AGENT=strtoupper(trim($_SERVER['HTTP_USER_AGENT']));
      if(strpos($iUSER_AGENT,"NOKIA")>0 || strpos($iUSER_AGENT,"WAP")>0 || strpos($iUSER_AGENT,"MIDP")>0 || 
strpos($iUSER_AGENT,"UCWEB")>0 )$is_wap == 1;
        }  
if($is_wap==1){header('Location:wap/index.php');exit;
}
?>