เรื่อง form อยู่ใน form เเล้วเวลา submit มันไม่ตรง form

<form name="frmMain" action="so_process.php" method="post" OnSubmit="return onDelete();">
			<table width="100%" class="table table-bordered" align="center">
            <thead>
              <tr height="50">
                <td width="20%"><h3>หมายเลข S/O : <?php echo $number_so;?></h3></td>
                <td width="50%"><h3>ชื่อลูกค้า : <?php echo $name_customer;?></h3></td>
                <td colspan="3" width="30%"><h3>&nbsp;&nbsp;&nbsp;วันที่เปิด : <?php echo $time;?>
                  <input name="name_customer" type="hidden" id="name_customer" value="<?php echo $name_customer;?>" />
                  <input name="time" type="hidden" id="time" value="<?php echo $time;?>" />
                  <input name="number_so" type="hidden" id="number_so" value="<?php echo $number_so;?>" />
                  <input name="date_shipping" type="hidden" value="<?=$date_shipping;?>" />
               </h3></td>
              </tr>
              <tr>
                <td colspan="5"><div align="center">รายระเอียดสินค้า</div></td>
              </tr>
              <tr>
                <td><div align="center">รหัสบาร์โค้ด</div></td>
                <td colspan="2"><div align="center">ชื่อสินค้า</div>                  </td>
                <td width="20%"><div align="center">จำนวน</div></td>
                <td>
                <div align="center">
                  ลบทั้งหมด
                    <input name="CheckAll" type="checkbox" id="CheckAll" value="Y" onclick="ClickCheckAll(this);" />
                </div></td>
              </tr>
              </thead>
			  <?php
	$sql5 = "select * from oder LEFT JOIN item ON oder.barcode_item = item.barcode_item where number_so = '$number_so'"; 
     $qr5 =dbQuery($sql5) or die("error $sql5");
	 $row =dbNumRows($qr5);
	
	$i =0;
while($objResult = dbFetchArray($qr5))
{
		$barcode_item = $objResult['barcode_item'];
		$number = $objResult['number'];
	$i = $i + 1;
	$status5 = $objResult["status"];
$sql="select  SUM(number),barcode_item from s_stock  Where barcode_item = '$barcode_item' group by barcode_item"; 
$qr =dbQuery($sql);
$rs=dbFetchArray($qr);
$number5 = $rs['SUM(number)'];
 $sql6="select  SUM(number),SUM(number_widen),barcode_item from oder  Where barcode_item = '$barcode_item' group by barcode_item"; 
     $qr6 =dbQuery($sql6);
$rs6=dbFetchArray($qr6);
$number6 = $rs6['SUM(number)'];
$number_widen6= $rs6['SUM(number_widen)'];
$balance = $number5-($number6-$number_widen6);
?>
              <tr>
                <td >
                <form method="post" name="edit" action="so_process.php?edit=edit">
                <input name="barcode_item" type="hidden" id="barcode_item" value="<?php echo $barcode_item;?>" />
                 
					  <input name="number1" type="hidden" id="Stock<?=$i;?>" value="<?php echo $balance+$number;?>"/>
                      <input name="hdnnumber" type="hidden" id="hdnnumber" value="<?php echo $number;?>" />
<div class="modal fade" id="myModal<?=$objResult["barcode_item"];?>" tabindex="-1" role="dialog" aria-labelledby="myModalLabel" aria-hidden="true">
  <div class="modal-dialog">
    <div class="modal-content">
      <div class="modal-header" align="center">
        <button type="button" class="close" data-dismiss="modal" aria-hidden="true">&times;</button>
        <h4 class="modal-title" id="myModalLabel">แก้ไขจำนวน</h4>
      </div>
      <div class="modal-body">
      <input type="hidden" name="category_id" value="<?=$objResult["barcode_item"];?>" />
      	<div class="col-md-10" align="center"><?=$objResult["name_item"];?></div><div class="col-md-2" align="center"><input name="number" type="text" id="number<?=$i;?>" onkeyup="check('<?=$i;?>');" value="<?php echo $number;?>" size="5" class="form-control" required /></div>
        <br />
      </div>
      <div class="modal-footer">
        <button type="button" class="btn btn-default" data-dismiss="modal">ปิด</button>
        <button type="submit"  class="btn btn-primary">ตกลง</button>
      </div>
    </div>
  </div>
</div>
</form><div align="center"><a href=""  data-toggle="modal" data-target="#myModal<?=$objResult["barcode_item"];?>"><?=$objResult["barcode_item"];?></a></div></td>
                <td colspan="2">&nbsp;&nbsp;&nbsp;<?=$objResult["name_item"];?>&nbsp;&nbsp;&nbsp;</td>
                <td><div align="center"><?=$objResult["number"];?></div></td>
                <td><div align="center">
				<input type="checkbox" name="chkDel[]" id="chkDel<?=$i;?>" value="<?=$objResult["barcode_item"];?>">
				<input name="hdnnumber_so<?=$i;?>" type="hidden" id="hdnnumber_so<?=$i;?>" value="<?=$objResult["number_so"];?>" size="5" />
				</div></td>
              </tr>
			  	<?php
}
?>
      </table>
	<div class="col-md-10"> </div>       <div class="col-md-2"> <input type="submit" name="btnDelete" value="Delete" class="form-control"></div>
<input type="hidden" name="hdnCount" value="<?=$i;?>">
            </form>