I have a small form for updating existing records.

I'm loading the Service IDs to the dropdown box using PHP. And when the user clicks the Load button, it is supposed to display the other details related to that ID in the textboxes below. Here is the code I have so far.
<html>
<head>
</head>
<body>
<?php
//Database initialization
require_once("db_handler.php");
$conn = iniCon();
$db = selectDB($conn);
$query = "SELECT * FROM taxi_services ORDER BY SID";
$result2 = mysql_query($query, $conn);
?>
<div id="upserv">
<b id="caption2">Update location</b>
<br/><br/>
<form name="upServForm" action="<?php echo $PHP_SELF; ?>" method="post" >
<?php
$dropdown = "<select name='codes'>";
while($row = mysql_fetch_assoc($result2))
{
$dropdown .= "\r\n<option value='{$row['SID']}'>{$row['SID']}</option>";
}
$dropdown .= "\r\n</select>";
?>
Service ID <?php echo $dropdown; ?> <input type="submit" value="Load" name="loadbtn">
<table width="300" border="0">
<tr>
<td>Name</td>
<td><input type="text" name="upName" style="text-align:right" value="<? echo $savedName; ?>" /></td>
</tr>
<tr>
<td>Cost</td>
<td><input type="text" name="upCost" style="text-align:right" value="<? echo $savedCost; ?>" /></td>
</tr>
<tr>
<td>Active</td>
<td><input type="checkbox" name="upActive" value="<? echo $savedActive; ?>" /></td>
</tr>
</table>
</div>
<br/>
<div id="buttons">
<input type="reset" value="Clear" /> <input type="submit" value="Save" name="updatebtn" />
</div>
</form>
<?php
if(isset($_POST["loadbtn"]))
{
$id = $_POST["codes"];
$query = "SELECT Name, Cost, Active FROM taxi_services WHERE SID = '$id' ";
$result = mysql_query($query, $conn);
$details = mysql_fetch_array($result);
$savedName = $details["Name"];
$savedCost = $details["Cost"];
$savedActive = $details["Active"];
}
?>
</body>
</html>
The query gets executed just fine but the data doesn't get displayed in the textboxes. Can anyone please tell me what I am missing here?
Thank you.
<?with<?php<?php ?>too but to no avail.