خطأ في عملية update

<?
$id1 = $_GET['id'];
$query = "SELECT * From tour where id= $id1 ";
$result = mysql_query($query);
while($rowApps1 = mysql_fetch_object($result))
{

$num = $rowApps1->id;
$loc = $rowApps1->subject;
$body = $rowApps1->body;
$date_ = $rowApps1->date_;
$file = $rowApps1->fileinfo;
}
?>
<td><div align="center">
<form action="<?= $_SERVER['PHP_SELF']; ?>" method="post" >
<div align="center">
<table width="98%" height="245" border="0" cellpadding="0" cellspacing="0">
<tr>
<td valign="top"><label> </label>
<label> </label>
<label> </label>
<table
width="100%" height="245" border="0" cellpadding="0" cellspacing="0" bordercolor="#111111" id="AutoNumber1" style="border-collapse: collapse">
<tr>
<td width="35%"><b>Tour location : <font color="#FF3300">*</font></b></td>
<td width="65%"><div align="left"> <? echo $loc; ?>
<select name =subject tabindex="0">
<option>Malaysia</option>
<option>China</option>
<option>Australia</option>
<option>India</option>
<option>Vietnam</option>
<option>Cambodia</option>
</select>
</div></td>
</tr>
<tr>
<td width="35%"><b> Tour valid date :</b></td>
<td width="65%"><div align="left">
<input type="text" name="date_" size="40" dir="ltr" tabindex="1" value="<? echo $date_; ?>" />
</div></td>
</tr>
<tr>
<td width="35%" valign="top"><b>Tour details: <font color="#FF3300">*</font></b></td>
<td width="65%"><div align="left">
<textarea rows="8" name="body" cols="40" tabindex="2" dir="ltr"><? echo $body; ?></textarea>
</div></td>
</tr>
<tr>
<td valign="top"> </td>
<td><div align="left">
<input name="file2" type="file" id="file2" align="right" tabindex="3"/>
choose the pdf file </div></td>
</tr>
</table></td>
</tr>
</table>
</div>
<p align="center"> </p>
<p>
<input name="Update" type="submit" id="Update" value="Update" />
</p></form>

<?
if(isset($Update))
{


$uploaddir = "files";
$name = $_FILES['file2']['name'];
$sub=$_POST["subject"];
$da=$_POST["date_"];
$bo=$_POST["body"];

$query = "update tour set subject='$sub' , date_='$da' , body='$bo' where id=$num";
$result = mysql_query($query);
echo "<br><br>Data updated. <br><br>\n";



}