คือต้องการให้แสดงข้อมูลที่มีชื่อเรื่องซ้ำกัน โดยชื่อเรื่องต้องตรงกับ ข้อมูลที่ทำการ GET id เข้ามาค่ะ

<?php
session_start();
if($_SESSION['username'] == "")
{
	echo"<script>alert('Please Login!');</script>";
	exit();
}
if($_SESSION['status'] != "ENDORSEE")
{
	echo"This page for sendosee only!";
	exit();
}
include('header.php');
include_once("conn.php");
$SQL = "SELECT * FROM user WHERE username = '".$_SESSION['username']."' ";
$Query = mysql_query($SQL);
$Result = mysql_fetch_array($Query);
?>
<style type="text/css">
    .box{
        padding: 9px 15px;
        margin-right: 0;
	    background:#C1CDCD;
	    border-radius: 5px 5px;
        font-size: 15px;
        color:#00000;
        border: none;
    }
</style>
<title>ติดตามเอกสารที่ขออนุมัติ</title>
<?php include('mainend2.php');?>
<h2 class="page-header">รายละเอียดเอกสาร</h2>
<h6><font color="#50526D"></font></h6>

<?php
    $db = mysql_select_db("qr");
    $SQL = "SELECT *  FROM document AS d1
            INNER JOIN department  AS d2 ON  (d1.to_dep_id = d2.dep_id) 
            INNER JOIN position  AS d3 ON  (d1.to_pos_id = d3.pos_id)
            INNER JOIN user AS d4 ON  (d1.to_pos_id = d4.pos_id)
            WHERE doc_id = '".$_GET["doc_id"]."'";      
    $Query = mysql_query($SQL);
    $Result = mysql_fetch_array($Query);
    if(!$Result){
	    echo "Not found Document ID=".$_GET["doc_id"];
    }else{
        /*...*/
    }
?>


<div class="box mt-4">
<div class="container mt-2 p-3">
    <form method="post" action="" class="addel" data-addel-hide="true" data-addel-add="3" data-addel-animation-duration="1000" enctype="multipart/form-data" name="doc_name" id="form1">
        <div class="form-row">
            <label for="validationDefault01" class="col-md-2 col-form-label"><h6>หัวเรื่อง</h6></label>
            <div class="form-group col-md-10">
                <?php echo $Result["doc_name"];?>
            </div> 
        </div>
        <?php date_default_timezone_set('Asia/Bangkok');?>
        <div class="form-row">
            <label for="inputEmail4" class=" col-md-2 col-form-label " ><h6>วันที่บันทึก</h6></label>
            <div class="form-group col-md-3 ">
                <input type="text" class="form-control" id="inputPassword4" value="<?php echo $Result["date_of_receipt"];?>" readonly="true" name="date_of_receipt">
            </div>

            <h6><label for="validationDefault03" class="mx-sm-3 col-form-label ">&nbsp;&nbsp;วันที่ออก&nbsp;</label></h6>
            <div class="form-group col-md-3">
                <div class='input-group date' >
                    <input type='text' class="form-control"  id='validationDefault03' name="doc_date" value="<?php echo $Result["doc_date"];?>" readonly="true"/>
                </div>
            </div>

            <h6><label for="" class=" mx-sm-3 col-form-label ">&nbsp;&nbsp;ที่&nbsp;&nbsp;&nbsp;</label></h6>
            <div class="form-group col-md-2">
                <input type="text" class="form-control"  id="inputPassword4" name="doc_number" value="<?php echo $Result["doc_number"];?>" readonly="true">
            </div>  
        </div>
        <div class="form-row">
            <label for="validationDefault04" class="col-md-2 col-form-label"><h6>ประเภทเอกสาร</h6></label>
            <div class="form-group col-md-3">
                <input type="text" class="form-control"  id="inputPassword4"  name="doc_class" value="<?php echo $Result["doc_class"];?>" readonly="true">
            </div>
       
        </div>
        <div class="form-row">
            <label for="exampleFormControlTextarea1 " class="col-md-2 col-form-label"><h6>เนื้อความย่อ</h6></label>
            <div class="form-group col-md-10">
            <?php 
                if ($Result['doc_explain'] == ''){ 
                    echo "-"; 
                }else{ 
                    echo $Result["doc_explain"];  
                }
            ?>
            </div>
        </div>
        
        <div class="form-row">
            <label for="exampleFormControlTextarea1 " class="col-md-2 col-form-label"><h6>หมายเหตุ</h6></label>
            <div class="form-group col-md-10">
            <?php  
                if ($Result['doc_note'] == ''){ 
                    echo "-"; 
                }else{ 
                    echo $Result["doc_note"];  
                }
            ?>
            </div>
        </div>


        </div>
        </div>
        <br>

        <h2 class="page-header">ติดตามเอกสารที่ขออนุมัติ</h2>

        <table class="table table-striped table-bordered table-hover table-sm">
<br>

        <?php
    $db = mysql_select_db("qr");
    $SQL = "SELECT *  FROM document AS d1
            INNER JOIN department  AS d2 ON  (d1.to_dep_id = d2.dep_id) 
            INNER JOIN position  AS d3 ON  (d1.to_pos_id = d3.pos_id)
            INNER JOIN user AS d4 ON  (d1.to_pos_id = d4.pos_id)
            WHERE doc_name = 'จัดซื้อพัสดุ'";        
    $Query = mysql_query($SQL);
    $Result = mysql_fetch_array($Query);
?>

<tr  class="text-center"> 
    <th scope="col">วันที่</th>
    <th scope="col">จากหน่วยงาน</th>
    <th scope="col">จากตำแหน่ง</th>
    <th scope="col" style="width:28%;">ส่งถึง</th>
    <th scope="col">ชื่อเรื่อง</th>
    <th scope="col">สถานะ</th>
</tr>
<?php date_default_timezone_set('Asia/Bangkok'); ?>

<?php
while($Result = mysql_fetch_array($Query)){
?>
<tr>
    <td><?php echo $Result["date_of_receipt"];?></td>
    <td class="text-center"><?php echo $Result["from_dep_id"];?></td>
    <td class="text-center"><?php echo $Result["from_pos_id"];?></td>
    <td class="text-center"><?php echo $Result["name"];?>  &nbsp;<?php echo $Result["lastname"];?></td>
    <td class="text-center"><?php echo $Result["doc_name"];?></td>
    <td class="text-center"><?php echo $Result["doc_status"];?></td>
</tr>
<?php
}
?>
</table>
<?PHP include('footer.php'); ?>