Code PHP ตรวจสอบสินค้าที่มีอยู่ใน Stock ค่ะ คือมันไม่ยอมดึง จำนวนสินค้ามาเช็คค่าอะค่ะ ช่วยแนะนำหน่อยค่ะ

<?
@session_start();
$sess_username=$_SESSION["valid_user"];
if($sess_username=="")
{
	echo"<br><font color='red'><center> กรุณาสมัครสมาชิกก่อนค่ะ !! </font>";
	echo"<meta http-equiv='refresh'content='2;url=member.php'>";	
	exit();
}
if(count($chkdel)==0){
	$chkdel=array();
}
for($i=0;$i<count($sess_id);$i++){
	if(!in_array($sess_id[$i],$chkdel)){
	$temp_id[]=$sess_id[$i];
	$temp_name[]=$sess_name[$i];
	$temp_price[]=$sess_price[$i];
	$temp_num[]=$num[$i];
	}
}
$sess_id=$temp_id;
$sess_name=$temp_name;
$sess_price=$temp_price;
$sess_num=$temp_num;

include "config.inc.php";

  	$sql1="select * from tb_product  where pro_id='$sess_id;'";
     $result1=mysql_query ($sql1);
     $re=mysql_fetch_array($result1)   ;
	 $pro_stock=$re[pro_stock];
if($pro_stock < $sess_num){     
	echo "<script>alert(' $pro_stock');history.back();</script>"; 
echo "<script>alert(' ขออภัยคะท่านสั่งสินค้าเกินจำนวนที่ร้านเรามีคะ');history.back();</script>"; 
}

if($calculate){
	echo "<meta http-equiv='refresh' content='3; url=basket.php'></center>";
} else if($complete){
	echo "<meta http-equiv='refresh' content='3; url=order.php'></center>";
	session_register("session_id");
	session_register("session_name");
	session_register("session_price");
	session_register("session_num");	
}
?>

<?
@session_start();
$sess_username=$_SESSION["valid_user"];
if($sess_username=="")
{
echo"<br><font color='red'><center> กรุณาสมัครสมาชิกก่อนค่ะ !! </font>";
echo"<meta http-equiv='refresh'content='2;url=member.php'>";	
exit();
}
if(count($chkdel)==0){
$chkdel=array();
}
for($i=0;$i<count($sess_id);$i++){
if(!in_array($sess_id[$i],$chkdel)){
$temp_id[]=$sess_id[$i];
$temp_name[]=$sess_name[$i];
$temp_price[]=$sess_price[$i];
$temp_num[]=$num[$i];
}
}
$sess_id=$temp_id;
$sess_name=$temp_name;
$sess_price=$temp_price;
$sess_num=$temp_num;

include "config.inc.php";

$sql1="select * from tb_product where pro_id='$sess_id;'";
$result1=mysql_query ($sql1);
$re=mysql_fetch_array($result1) ;
$pro_stock=$re[pro_stock];
if($pro_stock < $sess_num){ 
echo "<script>alert(' $pro_stock');history.back();</script>"; 
echo "<script>alert(' ขออภัยคะท่านสั่งสินค้าเกินจำนวนที่ร้านเรามีคะ');history.back();</script>"; 
}

if($calculate){
echo "<meta http-equiv='refresh' content='3; url=basket.php'></center>";
} else if($complete){
echo "<meta http-equiv='refresh' content='3; url=order.php'></center>";
session_register("session_id");
session_register("session_name");
session_register("session_price");
session_register("session_num");	
}
?>

include "config.inc.php";
$sql1="select * from tb_product where pro_id='$sess_id'";
$result1=mysql_query($sql1);
$re=mysql_fetch_array($result1) ;
$pro_stock=$re[pro_stock];
if($pro_stock < $sess_num){ 
echo "<script>alert(' $pro_stock');history.back();</script>"; 
echo "<script>alert(' ขออภัยคะท่านสั่งสินค้าเกินจำนวนที่ร้านเรามีคะ');history.back();</script>"; 
}