Dependent combo box drop-down in PHP MYSQL JQUERY Part III

<?php
include_once('db.php');

$showId=intval($_GET['show_name']);

// $query="SELECT * FROM state ";
$query="SELECT * FROM show_place WHERE show_id='$showId'";
$result=mysql_query($query);



?>

<select name="show_place" onchange="getShowDate(<?php echo $showId ?>,this.value)">
<option>Select</option>
<?php
  while($row=mysql_fetch_array($result))
{
echo"<option value=  ".$row[show_placeid].">$row[show_place]</option>";
}
?>
</select>