ขอถามหน่อยครับพอดีว่าลองหัดทำระบบคลังสินค้าครับอัพเดทข้อมูลไม่ผ่านคับ

ผมลองปริ้น

echo "<pre>";
print_r($_SESSION);
echo "</pre>";
exit();


Array
(
    [intLine] => 3
    [strProductID] => Array
        (
            [0] => 1
            [1] => 2
            [2] => 3
            [3] => 4
        )

    [strQty] => Array
        (
            [0] => 200
            [1] => 100
            [2] => 50
            [3] => 10
        )

)

<?php
session_start();


			if(!isset($_SESSION["intLine"]))
			{
				echo "ยังไม่มีรายการสั่งซื้อ";
				exit();
			}

			$serverName = "localhost";
			$userName = "root";
			$userPassword = "123456789";
			$dbName = "mydatabase";

			$objCon = mysqli_connect($serverName,$userName,$userPassword,$dbName);
			if (!$objCon) {
				echo $objCon->connect_error;
				exit();
			}
			?>
			<form name="form1" method="post" action="output.php">
			<table class="table no-margin">
			<thead>
			  <tr>
			  <td width="10">#</td>
				<td width="101">รหัสสินค้า</td>
				<td width="82">ชื่อสินค้า</td>
				<td width="82">ราคา</td>
				<td width="79">จำนวน</td>
				<td width="79">ยอดรวม</td>
			  </tr>
			</thead>
			<tbody>  
			<?php
			  $Total = 0;
			  $SumTotal = 0;

			  for($i=0;$i<=(int)$_SESSION["intLine"];$i++)
			  {
				  if($_SESSION["strProductID"][$i] != "")
				  {
					$strSQL = "SELECT * FROM product WHERE ProductID = '".$_SESSION["strProductID"][$i]."' ";
					$objQuery = mysqli_query($objCon,$strSQL);
					$objResult = $objResult = mysqli_fetch_array($objQuery,MYSQLI_ASSOC);
					$Total = $_SESSION["strQty"][$i] * $objResult["Price"];
					$SumTotal = $SumTotal + $Total;
				  ?>
				  <tr>
					<td><?php echo $i ;?></td>
					<td><?php echo $_SESSION["strProductID"][$i];?></td>
					<td><?php echo $objResult["ProductName"];?></td>
					<td><?php echo $objResult["Price"];?></td>
					<td><?php echo $_SESSION["strQty"][$i];?></td>
					<td><?php echo number_format($Total,2);?></td>
				  </tr>
				</tbody>  
				  <?php
				  }
			  }
				 
			  ?>
			    <tr>
				  <td colspan="2"></td>
				  <td></td>
				  <td></td>
				  <td>ยอดเงินสุทธิ</td>
				  <td><input type="text" name="" id="" size="10" value="<?php echo number_format($SumTotal,2);?>" readonly></td>
				</tr>
				<tr>
				  <td colspan="2"></td>
				  <td></td>
				  <td></td>
				  <td>เงินสดรับ</td>
				  <td><input name="Received" type="text" id="Received" size="10"></td>
				</tr>
				<tr>
				  <td colspan="2"></td>
				  <td></td>
				  <td></td>
				  <td>เงินทอน</td>
				  <td><input name="Refund" type="text" id="Refund" size="10"></td>
				</tr>
			</table>
			<br>
			<input name="Balance" type="hidden" id="Balance" value="<?php echo $SumTotal ;?>" size="10">
			<input name="Subtotal" type="hidden" id="Subtotal" value="<?php echo $Total ;?>" size="10">
			<input name="ProductName" type="hidden" id="ProductName" value="<?php echo $objResult["ProductName"];?>" size="10">						
        
         <h3>กรอกข้อมูลผู้สั่งซื้อสินค้า</h3>

			<table class="table no-margin">
				<tr>
				  <td width="80">รหัสลูกค้า</td>
				  <td width="250"><input type="text" id="CustomerID" name="CustomerID" tabindex="1" Class="form-control" placeholder="  ป้อนรหัสลูกค้า" required></td>
				</tr>
				<tr>
				  <td width="50">ชื่อลูกค้า</td>
				  <td width="250"><input type="text" name="txtName" id="Name" Class="form-control" required></td>
				</tr>
				<tr>
				  <td>ที่อยู่</td>
				  <td><textarea name="txtAddress" id="Address" Class="form-control" required></textarea></td>
				</tr>
				<tr>
				  <td>เบอร์โทร</td>
				  <td><input type="text" name="txtTel" id="Tel" Class="form-control" required></td>
				</tr>
				<tr>
				  <td>อีเมล์</td>
				  <td><input type="text" name="txtEmail" id="Email" Class="form-control" required></td>
				</tr>
			</table>
			  <br/><br/>
				<div>&nbsp;&nbsp;<input type="submit" name="Submit" class="btn btn-success" value="บันทึก">&nbsp;&nbsp;<a href="clear1.php" class="btn btn-warning">ยกเลิก</a>&nbsp;&nbsp;<a href="sale1.php" class="btn btn-primary">เพิ่มสินค้า</a></div>
			</form>
			<?php
			mysqli_close($objCon);
			?>