vbulletin forum post ?

I found these php code but its not working ..can you help me to find mistake

<?
 $mesaj = $_POST['mesaj'];


 
 function post ($kullanici,$sifre,$domain_,$topicle){
     global $mesaj;
     $user = $kullanici;
     $pass = $sifre;
     $url =  $domain_;
     $topicid = $topicle;
    

    $ua = curl_init();
    curl_setopt($ua , CURLOPT_URL, $url);
    curl_setopt($ua , CURLOPT_RETURNTRANSFER , TRUE);
    curl_setopt($ua , CURLOPT_REFERER, 'http://www.google.com');
    curl_setopt($ua , CURLOPT_USERAGENT, "Mozilla/5.0 (Windows; U;  Windows NT 5.1; tr; rv:1.9.2.7) Gecko/20100713 Firefox/3.6.7");
    curl_setopt($ua , CURLOPT_COOKIEFILE, dirname(__FILE__).'/cookies.txt');
    curl_setopt($ua , CURLOPT_COOKIEJAR, dirname(__FILE__).'/cookies.txt');
    curl_setopt($ua, CURLOPT_FOLLOWLOCATION, TRUE);
    $exec = curl_exec($ua);
    
    preg_match('/securitytoken" value="(.*?)"/',$exec,$securitytoken);
    curl_setopt($ua , CURLOPT_URL, ''.$url.'/login.php?do=login');
    curl_setopt($ua , CURLOPT_POST , TRUE);
    curl_setopt($ua , CURLOPT_POSTFIELDS,  'cookieuser=1&vb_login_username='.$user.'&vb_login_password='.$pass.'&s=&securitytoken='.$securitytoken[1].'&do=login');
    $exec = curl_exec($ua);

    curl_setopt($ua , CURLOPT_URL, $url .'/showthread.php?t='. $topicid);
    curl_setopt($ua , CURLOPT_POST, FALSE);
    $exec = curl_exec($ua);

    preg_match("/p=(\d{2,})/", $exec, $p);
    $p = $p[1];

    curl_setopt($ua , CURLOPT_URL, $url .'/newreply.php?do=newreply&noquote=1&p='. $p);
    curl_setopt($ua , CURLOPT_POST, FALSE);
    $exec = curl_exec($ua);
    //echo $exec;
 
    preg_match('/securitytoken" value=(.*)"/',$exec,$securitytoken);


    curl_setopt($ua , CURLOPT_URL, ''.$url.'/newreply.php?do=postreply&t='. $topicid);
    curl_setopt($ua , CURLOPT_POST, TRUE);
    curl_setopt($ua , CURLOPT_POSTFIELDS, 'do=postreply&t='.  $topicid .'&p='. $p  .'&subject=xxxxxxxxx&message='.$mesaj.'&securitytoken='.$securitytoken[1].'');

    $exec = curl_exec($ua);
    echo $exec; 
    curl_setopt($ua , CURLOPT_URL,$url);
    $info = curl_getinfo($ua);

    echo 'Took ' . $info['total_time'] . ' seconds to send a request to ' . $info['url'] .'<br />';
    echo curl_getinfo($ua, HEADER_OUT);
    curl_close($ua);
 }
 
  post("username here","password here","forumadress here","topicnumber here");
    
?>

PHP: