updating filtered mysql rows in php - php

Question

I'm trying to update different rows from mysql that they filtered by some record . in this code first the user should enter two input : classnumber and level .
records that they have this fields will show in table then the user should be able to update this records information . but the problem is all of records are in one table in mysql so their id is different I mean for example the first record that match with two inputs id is 2 and then the next one is 5 and next one 6 and ....
with this kind of situation how should I change the code below ?
<form id="searchform" method="post" dir="rtl" action="">
level :<input name="level" style="margin-top:5px; margin-left:6px;font-family: Tahoma,Geneva,sans-serif; font-size: 12px; margin-top: 5px; padding: 5px; width: 50px;" type="text" id="level" />
classnumber :<input name="classnum" style="margin-top:5px; margin-left:6px;font-family: Tahoma,Geneva,sans-serif; font-size: 12px; margin-top: 5px; padding: 5px; width: 50px;" type="text" id="classnum" />
<input style="margin-top:10px; margin-left:120px; font-size: 14px; padding: 5px 14px;" type="submit" value="جستجو" name="enter" />
</form>
<?php
if(isset($_POST['enter'])){
$sql="SELECT * FROM `".$tbl_name."` where classnum='".$_REQUEST['classnum']."' and level='".$_REQUEST['level']."' ";
$result=mysql_query($sql,$link);
$count=mysql_num_rows($result);
}
?>
<div class="cleaner h30"></div>
<br>
<form name="form1" action="" method="POST">
<center>
<div>
<div align="center" width = 615>
<table class="stats" cellspacing="0" width="615" border="1">
<tr>
<th width="20" scope="col" >Id</th>
<th width="60" scope="col">Name</th>
<th width="60" scope="col">Last Name</th>
<th width="42" scope="col">Midterm</th>
<th width="54" scope="col">Class mark</th>
<th width="42" scope="col">Final Quiz</th>
<th width="54" scope="col">State</th>
<th width="54" scope="col">Details</th>
</tr>
<?php
while($rows=mysql_fetch_array($result)){
$id[]=$rows['id'];
?>
<tr>
<td align="center">
<input name="id[]" type="text" id="id" value="<? echo $rows['id']; ?>" style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 10px;"></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 60px;" type="text" name="name[]" id="name" value= "<? echo $rows['name']; ?>" /></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 60px;" type="text" name="lastname[]" id="lastname" value= "<? echo $rows['lastname']; ?>" /></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 50px;" type="text" name="midmark[]" id="midmark" /></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 50px;" type="text" name="classmark[]" id="classmark" /></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 50px;" type="text" name="finalmark[]" id="finalmark" /></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 50px;" type="text" name="state[]" id="state" /></td>
<td align="center"><input style=" font-family: Tahoma,Geneva,sans-serif; font-size: 12px; padding: 5px; width: 50px;" type="text" name="details[]" id="details" /></td>
</tr>
<?php
}
?>
</table>
</div>
</div>
</center>
<input style="margin-top:10px; float:right; margin-right:175px; font-size: 14px; padding: 5px 14px;" type="submit" value="ثبت" name="Submit" />
</form>
<?php
// Check if button name "Submit" is active, do this
if(isset($_POST['Submit']))
{
for($i=0;$i<$count;$i++)
{
$sql1=mysql_query(" UPDATE `".$tbl_name."` SET midmark='".$_REQUEST['midmark'][$i]."' , classmark='".$_REQUEST['classmark'][$i]."' , finalmark='".$_REQUEST['finalmark'][$i]."' , state='".$_REQUEST['state'][$i]."' , details='".$_REQUEST['details'][$i]."' WHERE id='".$_REQUEST['id'][$i]."' "); $result1=mysql_query($sql1);
}
}
if($result1){
header("location:results.php");
}
mysql_close();
?>