รบกวนช่วยดูทีคะ ใช้ฟังก์ชั่น get ส่งค่าไปยังอีกหน้านึงแล้วแต่เหมือนกับว่าไม่เจอค่าที่หน้าเว็บนั้นคะ

<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<p>ค้นหาจาก Contact ที่ยังไม่ได้ตอบลูกค้า</p>
<?php
include_once "connect.php";
$sql="select * from customer where emp_edit='' ";
$rs=mysql_query($sql);
?>
<table width="1089" border="1">
  <thead>
  <tr>
  <td width="69" align="center">No.</td>
  <td width="129" align="center">Customer_Name</td>
  <td width="142" align="center">Customer_Contact</td>
  <td width="133" align="center">Customer_Comment</td>
  <td width="109" align="center">Ask Date</td>
  <td width="114" align="center">Ask Time</td>
  <td width="182" align="center">Employee_Reply</td>
  <td width="105" align="center">Edit</td>
  <td width="71" align="center">Delete</td>
  </tr>
  <tbody>
    <?php
	while($show=mysql_fetch_assoc($rs)){
	?>
    <tr>
    <td><? echo ++$n; ?></td>
    <td><?=$show['cus_name'];?></td>
    <td><?=$show['cus_contact'];?></td>
    <td><?=$show['cus_comment'];?></td>
    <td><?=$show['ask_date'];?></td>
    <td><?=$show['ask_time']; ?></td>
    <td><?=$show['emp_edit']; ?></td>
    <td><a href="edit_cus_contact.php?cus_id=<?=$show['cus_id'];?>">Edit</a></td>
    <td><a href="delete_cus_contact.php?cus_id=<?=$show['cus_id'];?>" onClick="return confirm('Are you sure to delete?');">Delete</a></td>
    </tr> <?php } ?>
    </tbody>
   </table>
</form>

<? session_start();
?>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<?php

include_once("connect.php");
$user=$_SESSION["username"];
$cus_id=$_GET['cus_id'];
$strsql=mysql_query("select * from customer where cus_id='$cus_id'");
$rs=mysql_fetch_assoc($strsql);
$cus_name=$rs[cus_name];
$cus_contact=$rs[cus_contact];
$cus_comment=$rs[cus_comment];
$emp_edit=$rs[emp_edit];

?>

<form name="form1" method="get" action="update_contact.php"> 
<table>
<tr>
<td width="365">

  <p>//ข้อมูลจะถูกส่งไปยัง update_contact.php    </p></td></tr>
  
  <tr><td>cus id <? echo $cus_id;?></td></tr>
    <tr>
  <td> cus name  
    <? echo $cus_name;?>    </td>
  </tr>
  <tr>
  <td> cus con    <? echo $cus_contact;?>     </td>
  </tr>
   <tr>
  <td> cus comment   
    <? echo $cus_comment;?>     </td>
  </tr>
 <tr>
  <td> emp edit  
    <input type="text" name="emp_edit" value="<? echo $user?>">     </td>
  </tr>
  

  
  <tr>
   <td align="right"><input type="submit" name="Submit" value="Update"></td>
   
   </tr>
  </p>


</table>
</form>

<?php
session_start();
include_once("connect.php");
$emp="$_SESSION[username]";
date_default_timezone_set('Asia/Bangkok');
$reply_date = date('Y-m-d');
$reply_time = date('H:i:s');
$cus_id=$_GET['cus_id'];
$strsql="update customer set emp_edit='$emp',reply_date='$reply_date',reply_time='$reply_time' where cus_id= '$cus_id' ";
$rs=mysql_query($strsql);
if(isset($rs))
{
	
	echo "Already Edit<br>";
	echo "<a href='index_admin.php'>Back To Admin Page</a>";
}
else
{
	mysql_error();
}

?>