<script src="../js/jquery-1.11.3.min.js"></script>
<script src="../js/bootstrap.min.js"></script>
<script type="text/javascript">
$(function(){
   $("#kalipkodu").change(function(){
      $("#tanimtext").html($("#kalipkodu option:selected").attr("rel"));
       
   });
});
</script>

<select name="kalipkodu" id="kalipkodu">
        <option value="-1">Kalıp Seçiniz</option>
        <?php
do {  
?>
		<option rel="<?php echo $row_rsKalipListele['Kalip_Tanim']?>" value="<?php echo $row_rsKalipListele['Kalip_Kodu']?>"><?php echo $row_rsKalipListele['Kalip_Kodu']?></option>

        <?php
} while ($row_rsKalipListele = mysql_fetch_assoc($rsKalipListele));
  $rows = mysql_num_rows($rsKalipListele);
  if($rows > 0) {
      mysql_data_seek($rsKalipListele, 0);
	  $row_rsKalipListele = mysql_fetch_assoc($rsKalipListele);
  }
?>
      </select> <input type="text" id="tanimtext" value=""/>