การแก้ไขข้อมูล - ผมมีปัญหาเรื่องแก้ไขข้อมูลสมมุติว่าผมแก้ไขข้อมูล

<?
$host="localhost";
$username="root";
$password="3118";
$db="dep";
$tb="service";
//h("../connect/connect.php");
$connect= mysql_connect( $host,$username,$password) or die ("ติดต่อกับฐานข้อมูล Mysql ไม่ได้ ");

mysql_select_db($db) or die("เลือกฐานข้อมูลไม่ได้");

$sql="select * from $tb ";

$db_query=mysql_db_query($db,$sql);

$result =  mysql_fetch_array ($db_query);
$id=$result[id];
$name=$result[name];
$sname=$result[sname];
$day=$result[day];
$month=$result[month];
$year=$result[year];
$t=$result[t];
$tel=$result[tel];
$location=$result[location];
$type=$result[type];
$maintainance=$result[maintainance];
$level=$result[level];
?>
<div id="Layer7"><img src="image/main page/images/template83_r1_c6.jpg" width="251" height="77" /> <img src="image/main page/images/template83_r1_c8.jpg" width="387" height="77" />
  &nbsp;&nbsp;&nbsp;&nbsp;
  <div id="Layer"></div>
</div>
<form name="form1" method="post" action="reply_user2.php">
<div id="apDiv5"><img src="image/TL1_dep.jpg" width="219" height="34" /></div>
<p align="center" class="style1">&nbsp;</p>
<div id="apDiv1"></div>
<div id="apDiv2"></div>
<div id="apDiv3"></div>
<div id="apDiv4"></div>
<p align="center" class="style1">&nbsp;</p>
<p align="center" class="style1 style2 style3">แจ้งสถานะซ่อม</p>
<div align="center"><span class="style4">ครุภัณฑ์:</span> 
  <input type="text" name="id" value="<? echo"$id"; ?>">
  
  
&span class="style2"><span class="style4">ชื่อ:</span>
    <input type="text" name="name" value="<? echo"$name";?>">
  </span>
<p align="center"><span class="style4">นามสกุล:</span><span class="style2">
    <input type="text" name="sname" value="<? echo"$sname";?>">
</span>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>

<p align="center"><span class="style4">เบอร์โทร:</span>
  <input type="text" name="tel" value="<? echo"$tel";?>">
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>
<p align="center"><span class="style2">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</span><span class="style4">สถานที่ตั้ง:</span>
  <input type="text" name="location" value="<? echo"$location";?>">
 <br>
  </p>
  <p align="center"><span class="style2">&nbsp;</span><span class="style4">&nbsp;ประเภท:</span>
    <input type="text" name="type" value="<? echo"$type";?>">
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<br>
  </p>
<p align="center"><span class="style2">&nbsp;&nbsp;</span><span class="style4">ประวัติซ่อม:</span>
    <textarea name="maintainance" cols="35" rows="4"><? echo"$maintainance";?></textarea>
<p align="center"><span class="style4">สถานะการซ่อม:</span>
  <input type="text" name="level" value="<? echo"$level";?>" />
<p align="center">&nbsp;</p>
<p align="center"> 
  <input type="submit" name="Submit" value="บันทึกข้อมูล">
  <input type="reset" name="Submit2" value="Clear">
</p>
<p align="center">&nbsp;</p>
<p align="center">&nbsp;</p>
</form>
<?
mysql_close($connect);
?>
</body>
</html>

<?
$host="localhost";
$username="root";
$password="3118";
$db="dep";
$tb="service";

$connect= mysql_connect( $host,$username,$password) or die ("ติดต่อกับฐานข้อมูล Mysql ไม่ได้ ");

mysql_select_db($db) or die("เลือกฐานข้อมูลไม่ได้");


$sql="update $tb set 
name='$name',sname='$sname',tel='$tel',location='$location',
type='$type',maintainance='$maintainance',level='$level' where id=$id";

//echo $sql;
$db_query=mysql_db_query($db,$sql);

echo "แก้ไขข้อมูลเรียบร้อยแล้ว ";

mysql_close();

?>
        </p>

  <form action="report_service.php" method="post" name="form1" target="_parent" id="form1">
    <label>
      <input type="submit" name="button" id="button" value="ดูข้อมูล" />
    </label>
  </form>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
  <div id="apDiv3"></div>
  <div id="apDiv4"></div>
  <p>&nbsp;</p>
  <p>&nbsp;</p>
</div>
</body>
</html>