รบกวนดูโค๊ดเพิ่มจำนวนสินค้าในตะกร้าสั่งซื้อสินค้าคะ

<form method ="post" action="basket_cal.php" name="form1">
<div align="center">
  <table width="800" height="643" border="0" cellpadding="0" cellspacing="0" bgcolor="#C9E758">
    <!--DWLayoutTable-->
    <tr>
      <td width="800" height="200" valign="top"><table width="100%" height="202" border="0" cellpadding="0" cellspacing="0">
        <!--DWLayoutTable-->
        <tr>
          <td width="800" height="202" valign="top"><div align="right"><a href="product.php?typeid=all">สินค้าทั้งหมด</a> | ค้นหาสินค้า | <a href="basket_add.php">ตระกร้าสินค้า</a> </div></td>
          </tr>
      </table></td>
    </tr>
    <tr>
      <td height="19">&nbsp;</td>
    </tr>
    <tr>
      <td height="424" valign="top">
        <?
if(count($sess_id)==0){
   echo "ยังไม่มีสินค้าในตระกร้า";
}
else{
  echo"<b>ตระกร้าสินค้า</b><br><br>";
  echo"<table width=100% align=center bgcolor=#CCCC33>";
  echo"<tr>";
  
  echo"<th>ลบ</th>";
  echo"<th>สินค้า</th>";
  echo"<th>จำนวน</th>";
  echo"<th>ราคา</th>";
  echo"<th>ราคารวม</th>";
  echo"</tr><br><br>";
  $num=0;
for($i=0; $i<count($sess_id); $i++){
  if($sess_name[$i]<>""){
	$total_unit=$sess_price[$i]*$sess_qty[$i];
	$total=$total+$total_unit;
	$price=number_format($sess_price[$i]);
	$t_unit=number_format($total_unit);
 	echo"<tr>";
	echo"<td align=center><input type=checkbox name=prd_dell[] 
	value=$sess_id[$i]></td>";
	echo"<td width=250>&nbsp;&nbsp;&nbsp;&nbsp;$sess_name[$i]</td>";
	echo"<td align=center>
	<input type=text name=prd_qty[] value=$sess_qty[$i] size=2 onkeypress=chknum()>
	</td>";
	echo"<td align=right>$price</td>";
	echo"<td align=right>$t_unit</td>";
  	echo"</tr>";
  }}
  echo"</table>";
  $t=number_format($total);
  echo"<div align=right>
  <b>ราคารวม&nbsp;&nbsp; $t &nbsp;&nbsp;บาท</b>
  <br><br>
  <input type=hidden name=btn value=1>
  <input type=submit name=calculate value=คำนวณใหม่>
  <input type=submit name=complete value=สั่งซื้อสินค้า></div>";
  
  ?></td></tr></table><? }?></form>
   
</div>

for($i=0; $i<count($sess_id); $i++){//id:1,3,5,7
if (!in_array($sess_id[$i],$prd_dell)){//1,3,5,ไม่ถูกต้อง
$temp_id[]=$sess_id[$i];
$temp_name[]=$sess_name[$i];
$temp_price[]=$sess_price[$i];
$temp_qty[]=$sess_qty[$i];
}
}
$sess_id=$temp_id;
$sess_name=$temp_name;
$sess_price=$temp_price;
$sess_qty=$temp_qty;
if($calculate){
print"<meta http-equiv='refresh'content='0;URL=basket_add.php'>";
}else if($complete){
print"<meta http-equiv='refresh'content='0;URL=prd_order.php'>";
}
?>