ผมสับสนมากเลยครับช่วยที แก้เท่าไรก็ไม่ได้ หมดปัญญาแล้วครับ โค้ดอัพโหลด

<?php
 header('Content-Type: text/html; charset=utf-8');
$id     =$_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 $gra=="" or $abs==""  ) {
echo "<h3>ERROR : กรุณากรอกข้อมูลให้ครบนะครับ<h3>";echo "<A HREF='history.back()'>คลิกเพื่อกรอกข้อมูลใหม่</A><BR><BR>";  exit();
}


if ($_FILES["abs"]["error"] > 0)
    {
    echo "Return Code: " . $_FILES["abs"]["error"] . "<br>";
    }
  else
    {
    echo "Upload: " . $_FILES["abs"]["name"] . "<br>";
    echo "Type: " . $_FILES["abs"]["type"] . "<br>";
    echo "Size: " . ($_FILES["abs"]["size"]) . " <br>";
    echo "Temp file: " . $_FILES["abs"]["tmp_name"] . "<br>";
	}
   
     if (!move_uploaded_file($_FILES["abs"]["tmp_name"], "/abs/" . $abs_new)) {
			echo "Error: " . "cannot move upload file to /abs/" . $abs_new;
		} else { echo "Stored in: " . "/abs/" . $abs_new; }
		
		{	$strSQL = "INSERT INTO senior_n  (p_id,p_name,p_gra,p_aca,p_abs_name,p_stu_fname,p_stu_sname,p_adv,p_numkey) values
('$id','$pn','$gra','$aca','$abs_new','$stu_fname','$stu_fname','$adv','$num') " ;
			$result = mysql_query($strSQL);
			if (!$result) {
				echo "error:".mysql_error()."<br>";
			} else {
				echo "add new record Complete<br>";
			}
		}

 
mysql_close();
echo"<script>window.location='http://senior-project-kus.orgfree.com/adminhome.php';</script>"; 
?>