PHP GoogleAnalyticsを携帯で利用する

<?php
  function mobile_analytics($uid = '', $domain = '')
  {
    echo '<!-- Google Analytics for mobile START -->';
 
    $var_utmac=$uid; //enter the new urchin code
    $var_utmhn=$domain; //enter your domain
    $var_utmn=rand(1000000000,9999999999);//random request number
    $var_cookie=$session; //cookie number
    $var_random=rand(1000000000,2147483647); //number under 2147483647
    $var_today=time(); //today
    $var_referer=$_SERVER['HTTP_REFERER']; //referer url
    $var_uservar='btmx_mobile';//$storeinfo['storeid']; //enter your own user defined variable
    $var_utmp=$_SERVER['REQUEST_URI']; // request uri
 
    $urchinUrl='http://www.google-analytics.com/__utm.gif?utmwv=1&utmn='.$var_utmn.'&utmsr=-&utmsc=-&utmul=-&utmje=0&utmfl=-&utmdt=-&utmhn='.$var_utmhn.'&utmr='.$var_referer.'&utmp='.$var_utmp.'&utmac='.$var_utmac.'&utmcc=__utma%3D'.$var_cookie.'.'.$var_random.'.'.$var_today.'.'.$var_today.'.'.$var_today.'.2%3B%2B__utmb%3D'.$var_cookie.'%3B%2B__utmc%3D'.$var_cookie.'%3B%2B__utmz%3D'.$var_cookie.'.'.$var_today.'.2.2.utmccn%3D(direct)%7Cutmcsr%3D(direct)%7Cutmcmd%3D(none)%3B%2B__utmv%3D'.$var_cookie.'.'.$var_uservar.'%3B';
 
    $header = '';
 
    //Set the language to that of the client so analytics can track it.
    if (!empty($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
      $header = 'Accept-language: '.$_SERVER['HTTP_ACCEPT_LANGUAGE'].'
';
    }
    //Set the user agent to that of the client so analytics can track it.
    if (!empty($_SERVER['HTTP_USER_AGENT'])) {
      $header = 'User-Agent: '.$_SERVER['HTTP_USER_AGENT'].'
';
    }
 
    $opts = array(
      'http'=>array(
        'method'=>'GET',
        'header'=>$header
      )
    );
 
    $handle = fopen($urchinUrl, 'r', false, stream_context_create($opts));
    $test = fgets($handle);
    fclose($handle);
 
    echo '<!-- Google Analytics for mobile END -->';
  }
mobile_analytics('UA-xxxxxx-x', 'サイトのドメイン');
?>