<?php 
$aktif                 = 1;
$sliderSorgu          = mysql_query("SELECT * FROM slider WHERE durum = '1' ORDEr BY sira ASC");
while($sliderSonuc = mysql_fetch_object($sliderSorgu))
{ ?>
    <div class="item <?php echo $aktif==1?"active":""; ?>">
        <img src="Dosyalar/Galeri/Resim/<?php echo $sliderSonuc->resim; ?>" alt="<?php echo $sliderSonuc->adi; ?>">
    </div>

<?php 
    if($aktif == 1)
        $aktif = 0;
}
?>