mysql query not work

<meta charset="UTF-8">
<pre>
<?
error_reporting(E_ALL & ~E_NOTICE);
$link = mysql_connect("localhost", ) or die(mysql_error());
$db = mysql_select_db("_sistem", $link) or die (mysql_error());


mysql_query("SET NAMES 'UTF8'");
mysql_query("SET character_set_connection = 'UTF8'");
mysql_query("SET character_set_client = 'UTF8'");
mysql_query("SET character_set_results = 'UTF8'");

echo "....<br>";
echo "Revisioned #6" . " Last modified: " . date ("F d Y H:i:s.", getlastmod()) . "<p>";

require('files/excel_reader/reader.php');
$connection = new Spreadsheet_Excel_Reader();
$connection->setOutputEncoding('UTF-8');

// Sistem seç:
$sistem = "artemis";

// Platform seç:
$platform = "all";
echo "Selected brand group is <b>$sistem</b> and platform is <b>$platform</b><br>";
if ($platform == "all") {
    $appKey = "";
    $appSecret = "";
} elseif ($platform == "ha") {
    $appKey = "616ba6e11a2";
    $appSecret = "oNnZsGB";
}   elseif($platform == "xx") {
        $appKey = "ae317a8";
        $appSecret = "1eNmx";
    } else {
    echo "Hangi sistem olduğu seçili ama platform seçili değil. İşlem sonlandırılıyor.";
    die;
}
$en = "_en";
$tr = "_tr";
$lang = "en";
$secsis._.$lang = "Seçili sistem ";
if ($sistem == "artemis") {
    $connection->read('files/xls_files/artemis.xls');
} elseif ($sistem == "bahariye") {
    $connection->read('files/xls_files/bahariye.xls');
    echo "$secsis_en $sistem";
} elseif ($sistem == "foneks") {
    $connection->read('files/xls_files/foneks.xls');
    echo "$secsis_en $sistem";
} elseif ($sistem == "patika") {
    $connection->read('files/xls_files/patika.xls');
    echo "$secsis_en $sistem";
} // if:/sistem biti?i.
echo "<u>Marka - Model - Stok - M2 - SS - Kategori - Stokkodu</u><br>";
for ($i = 2; $i < $connection->sheets[0]['numRows']; $i++) {
    for ($j = 1; $j <= $connection->sheets[0]['numCols']; $j++)
    $marka = $connection->sheets[0]['cells'][$i][4];
    $modell = $connection->sheets[0]['cells'][$i][3];
    $stok = $connection->sheets[0]['cells'][$i][7];
    $m2 = $connection->sheets[0]['cells'][$i][10];
    $ss = $connection->sheets[0]['cells'][$i][1];
    $kat = $connection->sheets[0]['cells'][$i][5];
    $stokkod1 = $connection->sheets[0]['cells'][$i][3];
    $stokkod2 = $connection->sheets[0]['cells'][$i][10];
    $stokkodu = "$stokkod1-$stokkod2";



    if ($sistem == "artemis" AND $marka = "Artemis Halı") {
    $model1 = str_replace(array(
    "Art.","080x",".",
    ),array(
    NULL,"80x",NULL,
    ),$modell);
    $model_trconv1 = array("Ğ","Ü","İ","Ş","Ö","Ç","ğ","ü","ı","ş","ö","ç"); $model_trconv2 = array("G","U","I","S","O","C","g","u","i","s","o","c"); $model_trconv = str_replace($model_trconv1,$model_trconv2,$model1);
    $model = rtrim($model_trconv);
    $stok_kodu = $model."-".$m2;
    $stokkod = str_replace(" ","-",$stok_kodu);
    mysql_query('update urun set adet = "'.$stok.'" where stokk = "'.$stokkod.'"') or die(mysql_error());
    }