ผมจะต้องทำยังไงดีครับ อัพโหลดไฟล์ใหม่เพื่อไปอัพเดตแล้วแต่มันไม่ยอมเปลี่ยน ต้องทำยังไงครับ

<?php
 
$id     =$_POST['id'];
$pn     =$_POST['pn'];
$num   =$_POST['num'];
$stu_fname   =$_POST['stu_fname'];
$stu_sname   =$_POST['stu_sname'];
$adv   =$_POST['adv'];
$room   =$_POST['room'];
$gra    =$_POST['gra'];
$aca    =$_POST['aca'];


$abs=$_FILES['abs']['tmp_name'];
$abs_name=$_FILES['abs']['name'];
$abs_size=$_FILES['abs']['size'];
$abs_type=$_FILES['abs']['type'];
$abs_new =$id.".pdf";



include("connect.php");



if ($id=="" or $pn=="" or $stu_fname=="" or $stu_sname=="" or $adv=="" or $num=="" or $room==""or $gra=="" or $abs==""  ) {
echo "<h3>ERROR : กรุณากรอกข้อมูลให้ครบนะครับ<h3>";echo "<A HREF='addform.php'>คลิกเพื่อกรอกข้อมูลใหม่</A><BR><BR>";  exit();
}


if (!$abs) { 
echo "<h3>ERROR : ไม่สามารถ Upload ABSTRACT ได้ครับ </h3>";
} else {
$array_last=explode(".",$abs_name);
$c=count($array_last)-1;
$lastname=strtolower($array_last[$c]) ;
if ($lastname=="pdf" ) {
copy($abs,"abs/".$abs_new);
 }
 }
 
 
  
 
$strSQL = "INSERT INTO senior_n  (p_id,p_name,p_gra,p_aca,p_abs,p_abs_name,p_stu_fname,p_stu_sname,p_adv,p_roomkey,p_numkey) values
('$id','$pn','$gra','$aca','$abs','$abs_new','$stu_fname','$stu_fname','$adv','$room','$num') " ;
mysql_query($strSQL) or die(mysql_error());
 



 
 
mysql_close();
echo"<script>window.location='adddata.php';</script>"; 
?>

<?php

$p_id     =$_GET['id'];
$p_name     =$_GET['pn'];
$p_numkey   =$_GET['p_numkey'];
$p_stu_fname   =$_GET['stu_fname'];
$p_stu_sname   =$_GET['stu_sname'];
$p_adv   =$_GET['p_adv'];
$p_room   =$_GET['p_roomkey'];
$p_gra    =$_GET['p_gra'];
$p_aca    =$_GET['p_aca'];


$abs=$_FILES['abs']['tmp_name'];
$abs_name=$_FILES['abs']['name'];
$abs_size=$_FILES['abs']['size'];
$abs_type=$_FILES['abs']['type'];
$abs_new =$p_id.".pdf";


include("connect.php");


 if ($_FILES["file"]["error"] > 0)
    {
    echo "Return Code: " . $_FILES["file"]["error"] . "<br>";
    }
  else
    {
    $array_last=explode(".",$abs_name);
$c=count($array_last)-1;
$lastname=strtolower($array_last[$c]) ;
if ($lastname=="pdf" ) {
move_uploaded_file($abs,"abs/".$abs_new);
     
      }
    }
 
$strSQL = "update senior_n set 
			p_id		=	'$p_id' 
			,p_name		=	'$p_name'
			,p_numkey		=	'$p_numkey'
			,p_stu_fname		=	'$p_stu_fname'
			,p_stu_sname		=	'$p_stu_sname'
			,p_adv		=	'$p_adv'
			,p_roomkey	=	'$p_room'
			,p_gra		=	'$p_gra'
			,p_aca		=	'$p_aca'
			
			where p_id		=	'$p_id' " ;
mysql_query($strSQL) or die(mysql_error());


//printf("Last inserted record has id %d\n", mysql_insert_id());

 
 
mysql_close();
echo"<script>window.location='adddata.php';</script>";

?>